OF WASHINGTON. 129 



Prof. Riley read an interesting letter from our fellow- 

 member, Mr. Ashmead, relating to various entomological 

 matters, and describing his [Ashmead 's] experiences and 

 work at Berlin, and particularly his first impressions of the 

 enormous extent of the insect collections of the Royal Mu 

 seum. Prof. Riley remarked that he was particularly pleased 

 at the statement that ' ' The large collections here have had a 

 depressing effect upon me, and I cannot conceive how one 

 little brain can take in all in one order," because it showed 

 that Mr. Ashmead realized the necessity of concentration in 

 order to do the best work. 



Prof. Riley also read a letter from an old correspondent, Mr. 

 S. S. Rathvon, of Lancaster, Pa., relating to certain unde 

 termined Phytonoimis larvae which occurred on the campus at 

 Lancaster, as well as other matters, and called attention to the 

 clear chirography and diction and the unflagging interest in 

 and knowledge of the entomology of to-day somewhat re 

 markable in a man over eighty years old, and suffering from 

 various severe bodily ailments. 



Prof. Riley then presented the following paper : 



A VIVIPAROUS COCKROACH. 



BY C. V. RII.EY. 



I present to the Society alcoholic specimens of a female 

 cockroach with her young, received recently from Dr. Carl F. 

 Gissler, of Brooklyn, who found it a little more than a year 

 ago in Brooklyn on a cabbage, and informed me, in communi 

 cating it, that it had given birth to the young viviparously. 

 I also present enlarged drawings of the female and of the 

 young. The species is Panchlora viridis, common in South 

 America, and peculiar as compared with our own cockroaches 

 in being of a light green color. The specimens interested me 

 greatly, because, so far as I have been able to ascertain, there 

 is no record of a viviparous Blattid, and after a careful exam 

 ination, -involving dissection of the abdomen of the specimen, 

 I see no reason whatever to doubt the accuracy of Dr. Gissler' s 

 statement. Several of the young had already been born, as 

 stated by him, but still others were in the abdomen ready to 



