NOTES. 352 
Norte VIIL, CHAPTER IL, p. 81. 
ANAL RESPIRATION IN CRAYFISH. 
Lereboullet (“Note sur une respiration anale observée chez plusieurs 
Crustacés ;*? Mémoires de la Société d’Histoire Naturelle de Strasbourg, 
IV. 1850) has drawn attention to what he terms “anal respiration ” in 
young crayfish, in which he observed water to be alternately taken into 
and expelled from the rectum fifteen to seventeen times in a minute. 
I have never been able to observe anything of this kind in the uninjured 
adult animal, but if the thoracic ganglia are destroyed, a regular 
rhythmical dilatation and closing of the anal end of the rectum at once 
sets in, and goes on as long as the hindermost ganglia of the abdomen 
retain their integrity. I am much disposed to imagine that the rhyth- 
mical movement is inhibited, when the uninjured crayfish is held in such 
a position that the vent can be examined. 
Note IX. Caaprer IL, p. 82, 
THE GREEN GLAND. 
The existence of guanin in the green gland rests on the authority 
of Will and Gorup-Besanez (Gelehrte Anzeigen, d. k, Baienzschen 
Akademie, No. 233, 1848), who say that in this organ and in the organ of 
Bojanus of the freshwater mussel, they found “a substance the reactions 
of which with the greatest probability indicate guanin,” but that they 
had been unable to obtain sufficient material to give decisive results, 
Leydig (Lehrbuch der Histologie, p. 467) long ago stated that the 
green gland consists of a much convoluted tube containing granular cells 
disposed around a central cavity. Wassiliew (“Ueber die Niere des 
Flusskrebses :” Zoologischer Anzeiger, I, 1878) supports the same view, 
giving a full account of the minute structure of the organ, and com- 
paring it with its homologues in the Copepoda and Phyllopoda. 
Notz X., CHAPTER IIL. p. 105. 
THE ANATOMY OF THE NERVOUS SYSTEM OF THE 
CRAYFISH. 
The details respecting the origin and the distribution of the nerves are 
intentionally omitted. See the memoir by Lemoine of which the title is 
given in the “Bibliography.” 
