INTRODUCTION. 



more impressed with his power and increasingly satisfied both 

 with his progress in biological studies and his sound general 

 knowledge of other sciences, anxious also, it may be, at the 

 same time that as much original inquiry as possible should be 

 carried on at Cambridge in my department, I either suggested 

 to him or acquiesced in his own suggestion that he should at 

 once set to work on some distinct research ; and as far as I 

 remember the task which I first proposed to him was an investi- 

 gation of the layers of the blastoderm in the chick. It must 

 have been about the same time that I proposed to him to join 

 me in preparing for publication a small work on Embryology, 

 the materials for this I had ready to hand in a rough form as 

 lectures which. I had previously given. To this proposal he 

 enthusiastically assented, and while the lighter task of writing 

 what was to be written fell to me, he undertook to work over 

 as far as was possible the many undetermined points and un- 

 satisfactory statements across which we were continually coming. 



During his two years at College his health had improved ; 

 though still hardly robust and always in danger of overwork- 

 ing himself, he obviously grew stronger. He rejoiced exceed- 

 ingly in his work, never tiring of it, and was also making his 

 worth felt among his fellow students, and especially perhaps 

 among those of his own college whose studies did not lie in 

 the same direction as his own. At this time he must have 

 been altogether happy, but a sorrow now came upon him. His 

 mother, to whom he was passionately attached, and to whose 

 judicious care in his early days not only the right development 

 of his strong character but even his scientific leanings were 

 due, had for some time past been failing in health, though her 

 condition caused no immediate alarm. In May 1872, however, 

 she died quite suddenly from unsuspected heart disease. Her 

 loss was a great blow to him, and for some time afterward I 

 feared his health would give way ; but he bore his grief quietly 

 and manfully and threw himself with even increased vigour 

 into his work. 



During the academic session of 1872 3, he continued steadily 

 at work at his investigations, and soon began to make rapid 

 progress. At the beginning he had complained to me about 

 what he considered his natural clumsiness, and expressed a fear 



