1885. j Morphology of Phylloglossum Drummondii. 445 



In connexion with the Mollusca certain points seem worthy of 

 special notice. 



In the first place, it is held by many comparative anatomists that the 

 lacunar system of Molluscs has a partly enterocoelous origin, or at 

 least has enterocoelous elements in its nature. If this be so, it is 

 interesting to note that some cells of the lacunar walls may be 

 glycogenous, for glandular surfaces seem to be specially characteristic 

 of the ectoderm and endoderm. Moreover, these cells are also to be 

 found on the mesenteries of Holothurians, which are undoubtedly 

 enterocoelous. 



In the second place, one of the greatest objections which can be 

 urged against the feasibility of water inception by Molluscs is 

 removed, if (1) the specific gravity and (2) the nutritive quality of 

 the blood can be maintained in spite of the process. It is supposed 

 that this would be accomplished by the discharge of the contents of 

 the glycogenous vesicles. 



Finally it is interesting to note, that one of the functions of the 

 vertebrate liver seems in Molluscs with ease to be performed outside 

 its domain, and this, moreover, in animals whose liver is essentially 

 a digestive gland. 



In conclusion I have to thank Professor Lankester and Professor 

 Foster, to whom, as also to Mr. Langley, Mr. Lea, and Mr. Gardiner, 

 I am very greatly indebted. 



X. " On the Development and Morphology of PhyUoglossum 

 Drummondii. Part I. Vegetative Organs." ByF. O.BOWER. 

 M.A., F.L.S., Regius Professor of Botany in the University 

 of Glasgow. Communicated by W. T. Thiselton Dyer, 

 M.A., C.M.G., F.R.S. Received'june 18, 1885. 



(Abstract.) 



The morphological history of Phylloglossum has up to the present 

 time rested on a very slender basis. The following brief summary 

 given by Sachs (" Textbook," 2nd English Edition, p. 463) 

 practically comprises the whole of it: — "A small Australian plant, 

 only a few centimetres high. It consists of a stem arising from a 

 small tuber, and bearing at its lower part a rosette of a few long leaves, 

 and one or more lateral roots ; it is prolonged above this as a thin 

 scape, and terminates in a spike of small leaves bearing the sporangia. 

 The plant is propagated by means of adventitious shoots, consisting 

 of a tuber with a rudimentary leafless bud ; in this respect it 

 resembles our native Ophrydece.'" 



The study of so reduced a form of a group, usually so remarkable 



