404 Miscellaneous. 



of the embryo a f unnel-shaped opening, circumscribed by tbo blasto- 

 dermic pad and corresponding to the canal which is seen in the 

 trout. 



Kupffer's vesicle only appears in the perch after the disappear- 

 ance of the closure-canal of the blastoderm. It has the same situa- 

 tion and the same form as in the stickleback. In a living embryo 

 I have distinctly seen, at its posterior part, on its dorsal surface and 

 above the vesicle, a small orifice with folded borders, which is very 

 probably the aperture of invagination of the vesicle ; but as yet I 

 have unfortunately been unable to assure myself, by sections, of the 

 continuity of this orifice with the vesicle, so as completely to confirm 

 Kupffer's description. 



Prof. Balbiani, who has verified my observations, agrees with 

 Balfour and Rauber in regarding Kupffer's vesicle as the homologue 

 of the primitive intestine of the Cyclostomi and Batrachians, its 

 external orifice representing the anus of Rusconi. As to the canal 

 originating from the closure of the blastoderm, it corresponds to the 

 blastopore of English writers, or to the mouth of the gastrula of 

 Hackel. In the Batrachia the blastopore and the anus of Rusconi 

 are confounded ; in the fishes these two orifices are distinct. — 

 Bull. Soc. Philom. de Paris, April 10, 1880. 



Completion of the Biology of the Aphides of the Galls of the Poplar 

 (Pemphigus bursarius, Linn.). By M. J. Liechtenstein. 



In his former paper on this insect * the author was compelled to 

 leave a gap in its history, namely the life of the insect from the 

 time of its quitting the gall as an emigrant until its return to the 

 trunk of the poplar as a pupiferous form. 



After unsuccessful attempts with the roots of grasses and other 

 plants, it occurred to him to try Filago germanica,he beingled to select 

 that plant because while he only knew the first two stages (founder 

 and emigrant) of Pemphigus bursarius, he only knew the last two 

 stages (gemmiparous and pupiferous) of Pemphigus filaginis, Boyer. 

 With this purpose he covered a plant of Filago with a bell glass, 

 and enclosed with it a poplar-gall filled with winged emigrants. 

 The plant was soon covered with the woolly secretion of Pemphigus 

 Jilaginis. At the same time (from 1st to loth July) all the plants 

 of Filago growing in the open round the bell glass were covered 

 with the same secretion and with the green and velvety black 

 Aphides constituting the gemmiparous phase f of that insect. 



The development of the winged pupiferous form proceeds very 

 rapidly ; three weeks suffice for it. On taking into his study the 

 bell glass and the plant of Filago covered by it, the author saw the 



* See 'Annals,' May 1880, vol. v. p. 433. 



t In this species the gemmiparous phase is simple, and not multiple as 

 in Phylloxera vastatrix ; and all the individuals proceeding from it are 

 wingred. 



