75 
inferior surface with minute hair-like papille for the emission of 
_ a viscid fluid, but which, from their organization, cannot possibly 
contribute to the formation of a vacuum.” Neither of these hypo- 
theses, nor the third, or simply mecianical one, is new, but the subject 
_ is far from being settled, and it appears to me to be unlikely that any 
one theory will apply in all cases, as there is an infinite variety in 
every part of the structure of the feet in insects, each doubtless best 
adapted to its own special purpose, or in some way modifying their 
power. 
In the ‘ Annales des Sciences Naturelles’ (1864, p. 64), M. E. Bau- 
delot has given us an account of his experiments on the influence of 
the nervous system on the ‘respiration of insects, which is “ completely 
opposed to the ideas generally admitted.” He considers that the respi- 
ratory function does not depend on any special organ (/oyer), but, on 
the contrary, that each abdominal ganglion is an organ of locomotive 
nervous power (¢rvervation). In the same work (p. 259) M. E. Clapa- 
réde has entered into long details on the sanguiferous system and 
circulation of the Lycosa. One of the most remarkable statements in 
this article is that the heart, an elongated vessel in the median line of 
the back, is surrounded on all sides (baigné de toutes parts) by venous 
blood, which is contained in a kind of sac, provisionally named 
“Jacune pericardiaque,” but whether this lacuna is the cavity of the 
pericardium he is unable to affirm. In another place, however, he 
says there is nothing to indicate the existence of a pericardium. 
Elsewhere he positively denies the accuracy of some of M. Emile 
Blanchard’s figures in his elaborate work the ‘ Organisation du Régne 
Animal.’ 
With regard to Dimorphism, an important fact has been recorded 
by Mr. Walsh (‘ Proceedings of the Entomological Society of Phila- 
delphia,’ March, 1864, p. 443). He finds that part of the galls of 
Quercus tinctoria produce males and females of Cynips spongifica in 
June; those that remain until October and November, and also in the 
following spring, produce Cynips aciculata, but females only. Mr. 
Walsh appears to prove that the latter, although’ widely different in 
many respects, is only a dimorphous form of Cynips spongifica.* 
I have already expressed an opinion that in some cases dimorphism 
may perhaps be dependent on second broods (‘ Proceedings’ of this 
Society, April 7, 1862, p. 72), and if attention was paid to this subject 
probably other instances might be found. 
* See also ‘Annals and Magazine of Natural History,’ vol. xiv. p. 400 (1864). 
