214 General Notes. [ March, 
Gand, has published a prize memoir of more than ordinary value. 
His conclusions are as follows: 1. The wall of the trachea com- 
prises three layers: one external, probably connective; a middle 
chitin-forming, and an internal chitinous layer. 2. The spiral 
its thickness alone ; but especially in its functions. 4. The tubu- 
lar trachez, and especially the intima of those organs, present 
numerous variations, even in a given group, like that of the 
winged insects, for example. The chitin- forming tunic of the 
trachea is not formed ‘by cells fused together, but it is on the con- 
trary a true epithelium. 6. The middle tunic remains independent 
along the whole length of the trachea. 7. The peritracheal circu- 
lation is anatomically impossible. 8. In many larve, the intima 
presents besides the spiral thread, other parts, differing by their 
properties. 
It will be remembered that Blanchard, and afterwards Agassiz, 
assumed that there was a circulation of blood between the trachea 
proper and its investing peritracheal membrane. Joly, and after- 
wards H. J. Clark of this country, maintained that this was 
anatomically impossible, and Macleod by experiments and dissec- 
tions shows that such must be the case. - 
= VITALITY oF HELIX ASPERA.—AImost incredible wg poet are 
found in the books concerning the vitality of snails. I must add 
another. August 24th, 1878, I ascended an old castle, or 
tower, near Queenstown, Ireland, and found between the stones a 
the common garden snail of Europe, Helix aspera. 
I iieatda three specimens, and having wrapped them in paper, 
ut them in my trunk. On my arrival home, October 28, on 
looking for my treasures, I found one was crushed. The other 
two I dipped i in water a few seconds, then put them in the fernery, 
and was delighted to see them crawl about. I could not get 
them to feed. One died in the following May, having been in 
confinement nine months. The other died in November, 1879, 
having lived thirteen months without food.—S. Lockwood, Free- 
hold, N. F. 
ZooLocicaL News.—In Forest and See for Jan. 29, Henry 
Youle Hind states that the salmon on the Labrador and New- 
foundland coast spawn in ‘the spring as well as in the autumn, 
i. ¢., that some spawn in the autumn and some in the spring.—— 
A blind Asellus-like Isopod Crustacean has been ices by 
Prof. Forel, at great depths, in Lake Leman; the eyes are rudi- 
mentary, while the general color of the animal is white. r. 
Darwin notices, in Nature, the fertility of hybrids from the com- 
mon and Chinese goose, and shows that the fertility is complete. 
: . W. Bates states that certain species of Longicorn ~ 
beetles mimic PITS beetles “ with great exactness, the a — 
