LIFE OF ALBANY HANCOCK, BY DB. EMBLETON. l3l 



then conimunicated with his Mend Mr. Hancock on the subject 

 of joining with him in the preparation of a more complete mono- 

 graph on the Tunicata than had before been contemplated, and 

 for which he proposed that Mr. Hancock should work out the 

 anatomy and physiology in the same manner as he had previ- 

 ously done with respect to the Nudibranchiata. 



The Eay Society was next consulted as to whether it would 

 be willing to publish the work thus contemplated. The society 

 having consented, and arrangements having been made, Mr. 

 Hancock at once laid aside other work, namely, " The Anatomy 

 and Physiology of the Cephalopoda," and at once applied his 

 vigorous powers to the Tunicata. 



The death of Mr. Alder in 1867 deprived Mr. Hancock of all 

 assistance from one who was thoroughly versed in the literature 

 of the subject, but still, anxious to carry out the wishes of his 

 friend, he laboured assiduously at the difficult task until pre- 

 vented by increasing sickness. 



The first result of these studies was that in 1868 Mr. Hancock 

 communicated to the Journal of the Linnaean Society, Zoology 

 IX., a paper "On the Anatomy and Physiology of the Tunicata." 

 This was only a prelude to the intended monograph, but never- 

 theless, though a succinct, it is an admirably simple and clear 

 description of the anatomy of many species of Simple and Com- 

 pound Tunicata, including many points of importance up to 

 that time unnoticed, and ending with a modest hypothetical 

 statement of some of the relations of the Tunicata, with the 

 Polyzoa on the one hand, and with the Lamellibranchiata on the 

 other, showing the great probability there is that ' ' the branchial 

 sac, the endostyle, the oral lamina, the branchial tubercle, and 

 the tentacular filaments of the inhalant tube of the Tunicata, are 

 new and distinct developments, and that all these organs have 

 equally their origin in the lining membrane or inner tunic of 

 Huxley, and have no homological representatives in the Polyzoa;" 

 and further, that "this interpretation of the fact leads to the 

 belief that the branchial sac (of the Tunicata) is the rudiment 

 and homologue of the Lamcllibranchiate gill." 



This hypothesis is founded upon anatomical data derived in 



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