xxvj DARWIN ii 



Again, on July 12, he writes: "I feel very doubtful how 

 far I shall succeed in answering Mivart. It is so difficult to 

 answer objections to doubtful points and make the discussion 

 readable. The worst of it is, that I cannot possibly hnnt 

 through all my references for isolated points — it would take 

 me three weeks of intolerably hard work. I wish I had your 

 power of arguing clearly. At present I feel sick of everything, 

 and if I could occupy my time and forget my daily discomforts, 

 or rather miseries, I would never publish another word. But 

 I shall cheer up, I dare say, soon, having only just got over 

 a bad attack. Farewell. God knows why I bother you about 

 myself. 



■ I can say nothing more about missing links than I 

 have said. I should rely much on pre-Silurian times ; but 

 then comes Sir W. Thompson like an odious spectre. 

 Farewell." 



I give these extracts because they serve to explain why 

 Darwin did not publish the systematic series of volumes 

 dealing with the whole of the subjects treated in the 

 " Origin." With his almost constant and most depressing 

 ill-health, the real wonder is that he did so much. We can, 

 therefore, fully understand why, when he had published the 

 " Descent of Man," in 1871, and the second editions of that 

 work and of the ■ Animals and Plants," in 1875, with the inter- 

 vening " Expression of Emotions," in 1872, he should devote 

 himself almost entirely to the long series of observations and 

 experiments upon living plants, which constituted his relaxa- 

 tion and delight, and resulted in that series of volumes which 

 are of the greatest value and interest to all students of the 

 marvels and mysteries of vegetable life. And when, in 1881, 

 he published his last volume upon "Worms," giving the 

 result of observations and experiments carried on for forty- 

 four years, he enjoyed the great satisfaction of its being a 

 wonderful success, while it was received by the reviewers 

 with unanimous praise and applause. 



During this latter period of his life I had but little corre- 

 spondence with him, as I had no knowledge whatever of the 

 subjects he was then working on. But he still continued to 



