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Obituary Notices of Fellows deceased. 



girdle of the Cartilaginous Fishes," published in the ' Zeitseh. Wiss. Zoologie/ 

 1880. 



Metchnikoff holds an important place beside his great fellow-countryman 

 and intimate friend, Alexander Kowalewsky (who died some years ago), in 

 the establishment of what may be called cellular embryology and the investiga- 

 tion of the early stages of development of inverfcebrata by following out the 

 process of cell-division and the arrangement of the early formed cells in 

 layers. In the 12 years 1875 to 1886, when his last embryological paper was 

 published, he produced many important memoirs on cellular embryology — 

 namely, on that of calcareous sponges (in which he showed that the inner and 

 outer primitive layers had been transposed in regard to their origin by Haeckel 

 and Miklucko-Macleay) ; on that of jelly-fishes, of Planarians, of Echinoderms, 

 of Ctenophora, and of Medusa?. These were accompanied by important 

 theoretical discussions and suggestions as to the ultimate ancestral origin of the 

 endoderm and the mesoblast. He also wrote on that curious group of minute 

 parasites, the Orthonectids, and on insect diseases. 



But the new departure in his fruitful career was approaching. It grew out 

 of his observations on living jelly-fishes and sponges and on the transparent 

 marine embryos of Echinoderms and the transparent floating mollusc 

 Phyllirhoe. In 1882, owing to political disturbances in the University of 

 Odessa, Metchnikoff migrated to Messina, the harbour of which is celebrated 

 among zoologists for its rich fauna of transparent floating larvae and adult 

 glass-like Pteropods and jelly-fishes. Here he developed his views, already 

 foreshadowed in 1880 (' Zoolog. Anzeiger '), on intracellular digestion exhibited 

 by the amoeboid cells of animal organisms, and published a series of papers in 

 which the name " phagocyte " is first applied to these cells. In this, as in 

 similar cases of discovery, neither Metchnikoff himself nor any of his friends 

 claimed that he was the first to observe all the facts leading to his generalisa- 

 tion. He was not the first to witness the ingestion of foreign particles, of 

 fragments of dead tissue, and even of bacteria, by the amoeba-like cells of the 

 animal body. He knew and cited the early observations of Haeckel on the 

 ingestion of pigment granules by the amoeboid blood-corpuscles of the sea- 

 slug Tethys. He knew and cited the numerous observations on the activity 

 of large amoeboid cells in assisting the resorption or rapid destruction of other 

 tissues in some special instances. He knew the observations of Jeffrey 

 Parker and others on the intracellular digestion of food particles taken into 

 their substance by the endoderm cells lining the digestive cavity of Hydra. 

 He knew Koch's observation of bacilli within a colourless vertebrate blood- 

 corpuscle, attributed by that observer to the active penetration of the blood- 

 corpuscle by the aggressive bacilli. These and other like instances were all 

 regarded as exceptional by their observers and not interpreted as evidences of 

 a definite and universal activity of the amoeboid cells of large physiological 

 significance. Metchnikoff was acquainted with the remarkable discoveries of 

 Cohnheim, Strieker, and others (in some of which I had a pupil's share during 

 my stay in the winters of 1869-70 and 1870-71 at Vienna and Leipzig 



