Miscellaneous. 163 
which surround the ege, which is thus enclosed in a pith-like enve- 
lope of asecretion resembling spiders’ threads. The secretory organs 
consist of two circlets of spinnerets placed on the sides of the 
abdomen, at the point occupied by the cornicles in the true Aphi- 
dinee. 
These eges, kept through the winter, began to hatch in the first 
days of April; I then transported the fragments of bark bearing 
these little animals to a young poplar placed for the purpose in my 
garden, and upon which I had ascertained that there were no galls 
last autumn. This operation was effected in the first days of the 
month of April, before my departure to the meeting of the French 
Association at Algiers. On my return I hastened to look at my little 
tree, and found it garnished with small galls of Pemphigus bursa- 
rius (easily recognized by their position at the base of the young 
buds) already as large as green peas. 
The test and counter tests having thus proved successful, I think 
that I may affirm that Pemphigus filaginis is only the gemmiparous 
and pupiferous form, 7. ¢. the third and fourth forms of Pemphigus 
bursarius. 
It may perhaps be objected that, the poplar being in the open air 
and incapabie of being covered with a bell glass, some error may 
still be possible; but this seems to me difficult. Nevertheless I am 
already preparing plants of Jago, which I shall keep shut up and 
under bells until the month of July, so as to make a rearing in the 
room, sheltered from all external influences. 
Moreover I have sent some of the same eggs which I have used 
in the above experiments to Mr. Riley at Washington, and to Mr. 
Monell at the Botanic Garden of St. Louis (Missouri); I am ex- 
pecting information from them; and if I can give rise to the same 
galls on the poplar in America, this will be an unanswerable argu- 
ment.—Comptes Rendus, May 2, 1881, p. 1063. 
Metamorphosis of Pedicellina. By M. J. Barrors. 
Most authors have hitherto supposed that the larva of Pedicellina 
passed directly into the adult by simple elongation of its lower 
part (the extremity of its aboral face), which became drawn out to 
form the peduncle. In 1877 I gave figures showing that matters 
did not go on in quite so simple a manner, and that, notwithstanding 
the great resemblance of the two forms, the larve of Pedicellina, 
like all the others, were subject to a period of very profound modi- 
fications. I was not then able to trace these modifications; but my 
recent thorough investigations of the subject enable me now to give 
a description of the passage, based upon observed facts. 
I. Fixation—The fixation takes place by the oral pole, and not, 
in accordance with the extant hypothesis, by the extremity (aboral 
pole) of the body. 
II. The digestive tube, accompanied by a portion of the vestibule, 
undergoes a rotation from in front backwards. In consequence of 
