1910.] NATURAL SCIENCES OF PHILADELPHIA. 271 



April 19. 

 J. Cheston Morris, M. D., in the Chair. 



Forty-seven persons present. 



The Publication Committee reported the reception of papers under 

 the following titles : 



"Stauroneis terryi D. B. Ward/' by T. Chalkley Palmer (April 11, 

 1910). 



"A revision of the North American Species of the Genus Ischnoptera 

 (Orthoptera)," by James A. G. Rehn and Morgan Hebard (April 12, 

 1910). 



"A new Diatom/' by T. Chalkley Palmer (April 19, 1910). 



Under the auspices of the Biological and Microscopical Section the 

 following communications were made: 



Jelly-pores in the Diatomacece. — Mr. Charles S. Boyer discussed 

 the observations of Otto Miiller, George Karsten and others upon the 

 occurrence and function of the jelly pore in the Diatomacese and de- 

 scribed it as found in certain species not heretofore recorded. As has 

 been stated, the production of a stipe or jelly cushion appears to be 

 its function. A more minute study of the habitat in various motile 

 and immotile species is requisite. The speaker dwelt upon the varying 

 conditions in earlier and later cell growth, of the tube and thallus 

 forming jelly, and of the relation between the raphe and the pore. 

 Suggestions were made as to the relation between the forms producing 

 the stipes and jelly cushions and those in which the protective devices 

 of many pelagic species were found to be siliceous. Drawings, original, 

 and from various authors, illustrated the remarks. 



Dr. Thomas S. Stewart, on the Hook-worm, Ankylostoma duo- 

 denale. (No abstract.) 



Unusual Forms of Myxomycetes. — Mr. Hugo Bilgram remarked 

 that in the early stages of their existence Myxomycetes are com- 

 posed of a slimy mass consisting of cells resembling amcebse, and 

 only in the last hours of their life do they assume the apparently 

 organized form of the well-known beautiful sporangia. 



The most simple species consist of a mass of spores enclosed in a 

 sporangium wall. Others develop within the sporangium a capillitium 

 often consisting of branching filaments, and in some genera, of isolated 

 fibres. In many genera the capillitium bears characteristic markings, 

 such as spines, warts or spiral ribs. In the process of maturation 

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