1850.] 9 



in color, and become almost motionless, which phenomena were followed by the 

 death of the animal. It occurred to him that, in such a state, there might be 

 exhibited some change in the character of its entophyta, as usually found in the 

 active condition of the animal. Upon removing the intestine of an individual 

 which had just died, he noticed that the entozoa which usually occupied the small 

 intestine, had passed into the rectum, and upon the surface of the mucous mem- 

 brane of the former, was developed a new plant. This is an oblate spheroidal 

 body, white in color, translucent, embossed upon the surface, and presenting, 

 when viewed by transmitted light, some resemblance to a minute bleached shell 

 of an Echinus ; by reflected light, it resembled a minute, white Lycoperdon. 

 This plant was strewed all over the mucous membrane, but grew in greatest 

 quantity along the course of filaments of Enterobrus, which appeared attached to 

 the mucous membrane throughout their length by it. When compressed it opened, 

 and spread into several leaf-like segments, and exuded a clear fluid with faint 

 granules. He thought that probably this plant might be another stage in the 

 existence of Enterobrus, for in the large number of individuals of Julus which he 

 had examined, upwards of 130, although he had observed the development of 

 Enterobrus from spore-like bodies, even to the formation of what he supposed to 

 be the sporangia, yet he had never been able to detect the formation of spores, 

 and when he saw this new plant enveloping the Enterobrus filaments, he sus- 

 pected that there might be a phenomenon here presented analogous to the alter- 

 nation of generation in certain animals, but had not yet satisfied himself that such 

 was the case. 



He also stated he had discovered a fourth species of Enterobrus in Polydesmus 

 virginiensis, and another entophyte analogous to Enterobrus growing in Poly- 

 desmus granulatus. The latter differs from Enterobrus in having numerous 

 globular cells at the free extremity of the principal cell. He adverted to the 

 several theories of cell formation, and said that in the last mentioned plant, in 

 the development of the globular terminal cells, the division of the permanent cell 

 wall followed the division of the cell contents. In conclusion, he observed, that 

 these matters would be more fully treated of hereafter, in a memoir which he was 

 preparing on the subject. 



February 2Qih. 

 Dr. Morton, President, in the Chair. 



The Committee on Conchology presented a report, recommending 

 that M. Lecoq's proposition, for an exchange of shells, be declined. 

 Adopted. 



The Committee on Mr. Conrad's paper, read February 12th, 1850, 

 reported in favor of publication in the Proceedings. 



