ments of facts in natural science, as if they were not only correct, but exhaustive; as if they might be dealt with deductively, in the same way as propositions in Euclid may be dealt with. In reality, every such statement, however true it may be, is true only relatively to the means of observation and the point of view of those who have enunciated it. So far it may be depended upon. But whether it will bear every speculative conclusion that may be logically deduced from it, is quite another question.

"Your father was building a vast superstructure upon the foundations furnished by the recognised facts of geological and biological science. In Physical Geography, in Geology proper, in Geographical Distribution, and in Paleontology, he had acquired an extensive practical training during the voyage of the Beagle. He knew of his own knowledge the way in which the raw materials of these branches of science are acquired, and was therefore a most competent judge of the speculative strain they would bear. That which he needed, after his return to England, was a corresponding acquaintance with Anatomy and Development, and their relation to Taxonomy-and he acquired this by his Cirripede work.

"Thus, in my apprehension, the value of the Cirripede monograph lies not merely in the fact that it is a very admirable piece of work, and constituted a great addition to positive knowledge, but still more in the circumstance that it was a piece of critical self-discipline, the effect of which manifested itself in everything your father wrote afterwards, and saved him from endless errors of detail.

"So far from such work being a loss of time, I believe it would have been well worth his while, had it been practicable, to have supplemented it by a special study of embryology and physiology. His hands would have been greatly strengthened thereby when he came to write out sundry chapters of the 'Origin of Species.' But of course in those days it was almost impossible for him to find facilities for such

work."

No one can look at the two volumes on the recent Cirripedes, of 399 and 684 pages respectively (not to speak of the volumes on the fossil species), without being struck by the immense amount of detailed work which they contain. The forty plates, some of them with thirty figures, and the fourteen pages of index in the two volumes together, give some rough idea of the labour spent on the work.* The state of knowledge, as regards the Cirripedes, was most unsatisfactory at the time that my father began to work at them. As an illustration of this fact, it may be mentioned that he had even to re-organise the nomenclature of the group, or, as he expressed it, he "unwillingly found it indispensable to give names to several valves, and to some few of the softer parts. of Cirripedes." It is interesting to learn from his diary the amount of time which he gave to different genera. Thus the genus Chthamalus, the description of which occupies twenty-two pages, occupied him for thirty-six days; Coronula took nineteen days, and is described in twenty-seven pages. Writing to Fitz-Roy, he speaks of being "for the last half-month daily hard at work in dissecting a little animal about the size of a pin's head, from the Chonos archipelago, and I could spend another month, and daily see more beautiful structure."

Though he became excessively weary of the work before the end of the eight years, he had much keen enjoyment in the course of it. Thus he wrote to Sir J. D. Hooker (1847 ?) : "As you say, there is an extraordinary pleasure in pure observation; not but what I suspect the pleasure in this case is rather derived from comparisons forming in one's mind with allied structures. After having been so long employed in writing my old geological observations, it is delightful to use one's eyes and fingers again." It was, in fact, a return to

* The reader unacquainted with Zoology will find some account of the more interesting results in Mr. Romane's article on Charles Darwin" ('Nature' Series, 1882).

+ Vol. i. p. 3.

the work which occupied so much of his time when at sea during his voyage. His zoological notes of that period give an impression of vigorous work, hampered by ignorance and want of appliances; and his untiring industry in the dissection of marine animals, especially of Crustacea, must have been of value to him as training for his Cirripede work. Most of his work was done with the simple dissecting microscope-but it was the need which he found for higher powers that induced him, in 1846, to buy a compound microscope. He wrote to Hooker:-"When I was drawing with L., I was so delighted with the appearance of the objects, especially with their perspective, as seen through the weak powers of a good compound microscope, that I am going to order one; indeed, I often have structures in which the is not power enough."

During part of the time covered by the present chapter, my father suffered perhaps more from ill-health than at any other time of his life. He felt severely the depressing influence of these long years of illness; thus as early as 1840 he wrote to Fox: "I am grown a dull, old, spiritless dog to what I used to be. One gets stupider as one grows older I think." It is not wonderful that he should so have written, it is rather to be wondered at that his spirit withstood so great and constant a strain. He wrote to Sir J. D. Hooker in 1845: "You are very kind in your enquiries about my health; I have nothing to say about it, being always much the same, some days better and some worse. I believe I have not had one whole day, or rather night, without my stomach having been greatly disordered, during the last three years, and most days great prostration of strength: thank you your kindness; many of my friends, I believe, think me a hypochondriac."

for

Again, in 1849, he notes in his diary:-" January 1st to March 10th.-Health very bad, with much sickness and failure of power. Worked on all well days." This was written just before his first visit to Dr. Gully's Water-Cure Establishment at Malvern. In April of the same year he wrote:-"I

believe I am going on very well, but I am rather weary of my present inactive life, and the water-cure has the most extraordinary effect in producing indolence and stagnation of mind: till experiencing it, I could not have believed it possible. I now increase in weight, have escaped sickness for thirty days." He returned in June, after sixteen weeks' absence, much improved in health, and, as already described (p. 108), continued the water-cure at home for some time.]

C. Darwin to J. D. Hooker.

Down [October, 1846]. heard from Sulivan *

MY DEAR HOOKER,-I have not lately; when he last wrote he named from 8th to 10th as the most likely time. Immediately that I hear, I will fly you a line, for the chance of your being able to come. I forget whether you know him, but I suppose so; he is a real good fellow. Anyhow, if you do not come then, I am very glad that you propose coming soon after. . . .

I am going to begin some papers on the lower marine animals, which will last me some months, perhaps a year, and then I shall begin looking over my ten-year-long accumulation of notes on species and varieties, which, with writing, I dare say will take me five years, and then, when published, I dare say I shall stand infinitely low in the opinion of all sound Naturalists-so this is my prospect for the future.

Are you a good hand at inventing names. I have a quite new and curious genus of Barnacle, which I want to name, and how to invent a name completely puzzles me.

By the way, I have told you nothing about Southampton. We enjoyed (wife and myself) our week beyond measure: the papers were all dull, but I met so many friends and made so many new acquaintances (especially some of the Irish Naturalists), and took so many pleasant excursions. I

* Admiral Sir B. J. Sulivan, formerly an officer of the Beagle.

#

wish you had been there. On Sunday we had so pleasant an excursion to Winchester with Falconer,* Colonel Sabine, and Dr. Robinson, and others. I never enjoyed a day more in my life. I missed having a look at H. Watson. I suppose you heard that he met Forbes and told him he had a severe article in the Press. I understood that Forbes explained to him that he had no cause to complain, but as the article was printed, he would not withdraw it, but offered it to Forbes for him to append notes to it, which Forbes naturally declined. . .

C. Darwin to J. D. Hooker.

Down, April 7th [1847 ?].

MY DEAR HOOKER,-I should have written before now, had I not been almost continually unwell, and at present I am suffering from four boils and swellings, one of which hardly allows me the use of my right arm, and has stopped all my work, and damped all my spirits. I was much disappointed at missing my trip to Kew, and the more so, as I had forgotten you would be away all this month; but I had no choice, and was in bed nearly all Friday and Saturday. I congratulate

* Hugh Falconer, born 1809, died 1865. Chiefly known as a palæontologist, although employed as a botanist during his whole career in India, where he was also a medical officer in H. E. I. C. Service; he was superintendent of the Company's garden, first at Saharunpore, and then at Calcutta. He was one of the first botanical explorers of Kashmir. Falconer's discoveries of Miocene mammalian remains in the Sewalik Hills, were, at the time, perhaps the greatest "finds" which had been made. His book on the subject, Fauna Antiqua Sivalensis,' remained unfinished at the time of his death.

The late Sir Edward Sabine, formerly President of the Royal Society, and author of a long series of memoirs on Terrestrial Magnetism. The late Dr. Thomas Romney Robinson, of the Armagh Observa

tory.

# The late Hewett Cottrell Watson, author of the 'Cybele Britannica,' one of a most valuable series of works on the topography and geographical distribution of the plants of the British Islands.