278 PROCEEDINGS OF THE SOCIETY OF 
accommodation and refraction of the eye. In a subsequent memoir he hag 
reviewed the opinions of M. Donders on astigmatism or irregularities of refrac- 
tion in the larger circles of the eye, an irregularity which always exists, more 
or less, but which in some cases may considerably alter the vision. 'The irreg- 
ular curvature of the cornea is ordinarily the cause of it, but that ot vhe erys- 
talline also exists, and the result is that cylindrical glasses of different focal 
power may be eligibly employed. Numerous details are entered into respect- 
ing the effects of asiigmatism and the proper means for ascertaining the cause, 
as well as supplying a remedy by a judicious choice of glasses. 
The composite eyes of arthropods form the subject of a special memoir by 
M. Dor, printed in the Bibliotheque Universelle tor December, 1861. In this 
the author, after reviewing the opinions propounded by anatomists, gives an 
account of direct experiments made by himself on the transmission of images 
through the cornea of sundry insects, and arrives at the conclusion that every 
facet of the composite eye is analogous to the single eye of one of the verte- 
brata—the cupuliform envelope being analogous to the retina. 
M. Claparede read a memoir on the oligochetous worms of the environs of 
Geneva. These animals, having until now been little studied, have conse- 
quently presented a great number of new species and even new genera. 
Figures delineated by the author make us acquainted with some of them, but 
his chief object has been to describe the singular modifications of the repro- 
ductive apparatus. This apparatus, analogous to that of certain annelida 
(Pachydrilus) previously described by our author, shows that the excretory 
organ of the segments becomes now a vas deferens and an oviduct, and now a 
receptacle of the semen. ‘The oligochetze live in fresh water, but as marine ani- 
mals always offer a wider field to the researches of zoologists, our learned sec- 
retary has not failed to visit, as often as circumstances would permit, the shores 
of the ocean. A sojourn in Normandy has enabled him to study the Turbel- 
laria and the Tubularia, whose development and mode of reproduction offered 
him some remarkable peculiarities. As one of the fruits of this excursion, he 
has designed a series of plates relative to the embryology of marine worms, 
which were exhibited to this Society. Dr. W. Marcet communicated to us 
from London the result of some observations which he has been making on the 
gastric juice of the dog. When this juice is secreted under the influence of 
cartilaginous bones, it contains a peculiar substance analogous to the peptone 
of Lehmann. 
BOTANY. 
Professor Marect presented an analysis of the labors of M. Daubeny on the 
absorption of different substances, particularly poisonous ones, by the roots of 
plants, (Beblioth. Univ. Archiv. Se., February, 1862.) M. Thury, who has 
been for some time occupied with a treatise on vegetable physiology, recapitu- 
lated the experiments of divers authors on the transpiration of vegetables ; he 
has repeated many of them, and among other results has satisfied himself that 
the phenomenon, as had been asserted, continues when the plant is placed in 
water. 
It has been said that the egret or tuft of the composite is often separated 
from the body of the grain, and hence does not favor the dissem‘nation, as had 
been supposed. M. Thury, having observed on one of the summits of the 
Jura large quantities of the grains of the Cirsiwm transported thither by the 
winds, ascertained that three out of thirty still bore the seeds with them. The 
compiler of the present report, being in habits of correspondence with divers 
travellers, communicated interesting letters from M. Sagot on the flora of 
Guiana, and of M. Welwitsch on the vegetation of the high country of Huilla, 
in the interior of southwestern Africa, ( Bibhioth. Univ., July, 1861.) M. Duby 
gave an account of a memoir published by M. Bail on an hypoxylon which 
propagates its mycelium in the interior of aged trunks of trees. 
