On the Uterine Villiform Papules of Pteroplataea micrura. 359 



March 19, 1891. 



Mr. JOHN EVANS, D.C.L., LL.D., Treasurer and Vice-President, 



in the Chair. 



The Bight Hon. Lord Hannen was admitted into the Society. 



The Presents received were laid on the table, and thanks ordered 

 for them. 



The following Papers were read : 



" On the Uterine Villiform Papillae of Pteroplatcea micrura, 

 and their Relation to the Embryo, being Natural Histoiy 

 Notes from H.M. Indian Marine Survey Steamer 'Inves- 

 tigator,' Commander R. F. Hoskyn, R.N., Commanding. 

 No. 22." By J. WOOD-MASON, Superintendent of the Indian 

 Museum and Professor of Comparative Anatomy in the 

 Medical College of Bengal, and A. ALCOCK, M.B., Surgeon. 

 I.M.S., Surgeon-Naturalist to the Survey. Communicated 

 by Professor M. FOSTER, Sec. R.S. Received February 24, 

 1891. 



Contents. 



L. Preliminary Historical Sketch. 



I 2. Recent Observations on the Uterine Villi of some Indian Rays. 

 3. The Uterus and Embryo of Pteroplatcea micrura, and the Relation of the 

 Uterine Villiform Papillae (or Trophonemata) to the Embryo. 



1. Preliminary Historical Sketch. 



That in the females of several Selachioids and Batoids the mucous 

 brane of the terminal portion of the oviduct, or uterus, is pro- 

 ed with glandular structures which secrete an albuminous fluid 

 tined in some way or other for the nourishment of the developing 

 bryo is a bionomic phenomenon which has attracted the attention 

 numerous physiologists and histologists, though, as far as we are 

 are, it has never been fully followed out. 

 Concerning the intra-uterine arrangements for the protection and 

 trition of the egg or embryo among Selachians, Gegenbaur 

 ('Grundziige der Vergleich. Auat.,' p. 875) writes : " The terminal 

 ivision of the oviduct of the Selachians, which has already been 

 rationed as functioning as uteras, also differs from the rest of the 

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