26 Crust . 
CRUSTACEA. 
Excretion in Brachyura ; Marciial. 
For an account, mainly physiological, of the digestive organs of the 
Grab, see Stamati. 
Appendages. 
Palps of Crustacea are not homologous with those of Insecta. The real 
hornologues of the latter are the endopodites of the second pair of 
maxillae and the three pairs of maxillipedes. The maxillipedes of Crus- 
tacea — at all events, of the Brachyura — are not used in seizing food. 
The mandibles alone in Crabs are masticatory. The mandibular palp has 
.no directive function, as suggested by Duges and Rolleston, nor has it 
been observed so to act in other Crustacea. Isopoda and Amphipoda are 
not seriously affected by loss of the endopodites of the maxillipedes. 
Plateau (2). 
Amans, in discussing the organs of aquatic locomotion, touches on 
Crustacea ( Apus and Langustus), p. 126. 
Bergendal records the occurrence of claspers in certain female Cray- 
fish. 
Abnormal chelae in Brachyura are described by le S^ni&chal. 
I Y. — PHYSIOLOGY. 
Schwarz describes the so-called mucous gland in Cypris monacha. He 
finds that its function is to isolate the spermatozoa which lie collected in 
masses in front of it, and to pump them onward. Morphologically it is 
an invagination of the vas deferens. 
There are two forms of Amcehocites to be observed in Astacus — 
granular and hyaline. These represent two stages, the granular being 
perfect and functional. Their function has no relation to haomatosis, but 
they contain in the granules the ferment which assists in assimilating the 
peptones, &c. Gattaneo. 
Petit finds that the lesion of the left side of the supra-oesophageal 
ganglion of Carcinus mcenas results in the animal describing a series of 
circles in the direction of the hands of a watch, but the head may be 
directed centrally or peripherally. The motion was reversed on lesion of 
the right side. 
For the structure of the test of Arthropoda , see Pouciiet. 
The cutaneous glands of the Crab ; Pouciiet & Wertheimer. 
Biedermann concludes that all the observed consequences of indirect 
stimulation of the claw muscles of the Crab seem to find their simplest 
explanation in the supposition that each of the two muscles is provided 
with two functionally distinct inhibiting and stimulatory nerves. In 
several respects, as Gaskell points out, there are analogies between the 
innervation conditions of the cardiac muscles of Vertebrates and those of 
the claw muscles of Crabs. 
For an account of the glutiniferous gland and of the eyes of Ampe- 
liscidce } see Della Valle. 
The striped muscle in Arthropoda is discussed by Gehuciiten. 
