The blow is indeed felt by us to be one of dire severity, the more so because we only had about a fortnight's warning of its advent. My sister did not pass through much suffering, but there was something painfully pathetic about her death, not only because she was so young and had always been so strong, but also because the ties of affection by which she was bound to us, and we to her, were more than ordinarily tender. And when in her delirium she reverted to the time when our positions were reversed, and when by weeks and months of arduous heroism she saved my life by constant nursing--upon my word it was unbearable.[15] The blank which her death has created in our small family is very distressing. She always used to be so proud of my work that I feel that half the pleasure of working will now be gone--but I do not know why I am running on like this. Of course it will give me every pleasure to go to Down before leaving for Scotland. If you have no preference about time, I suppose it would be best to go when you return home in May, as the onions might possibly be then ready for grafting. Unless, therefore, I hear from you to the contrary, I shall write again some time between the middle and end of May. Then came a second appearance at the British Association. Mr. Romanes was asked to deliver one of the evening lectures at the meeting of 1878, which took place at Dublin. The subject was animal intelligence, and seems to have excited a good deal of attention. The following letters relate to the lecture and to his book on Animal Intelligence: _To C. Darwin, Esq._ 18 Cornwall Terrace, Regent's Park, N.W.: June 18.