EFFECTS ON THE HIGHER INVERTEBRATES 59 



Kerb ('10) found that Daphnia during starvation may undergo repeated 

 ecdysis, moulting in spite of rapid decrease in body weight (from 105-111 mg. 

 to 24-28 mg. in n days). Lipschiitz ('13) cites similar observations by Knor- 

 rich ('01) and Wolff ('10). 



Among the Malacostraca, Haller (cited by Lucas, 1826) stated that the crab, 

 Cancer maurinus, can endure a starvation period of eighteen months. Mead 

 ('00) noted incidentally that the relations of nutrition and growth in the lobster 

 {Homarus) are similar to those already stated for the starfish. Przibram ('07) 

 described the regeneration of appendages in certain Crustacea (Trypton spongi- 

 cola, etc.) and concluded: "But not only may the means of regeneration and 

 compensation be clearly shown to occur in this case but also reduction is involved 

 to an appreciable degree, especially if the crayfish is starved during the experi- 

 ment. Then each moult shows the shedding of a smaller skin and the animal is 

 at the end of the transposition in all dimensions smaller than at the time of the 

 operation." 



Irvine and Woodhead ('88, '89) experimented with common edible shore 

 crabs {Cancer) which, after ecdysis, were placed in artificial sea-water. They 

 were found able to obtain the calcium carbonate necessary for the calcareous 

 exoskeleton when CaCl2 is the only calcium salt present in the sea-water, but 

 cannot utilize CaSo4 for this purpose. J. Loeb ('11) found that the marine 

 Gammarus dies quickly in distilled water, even when made isotonic by addition 

 of sugar solution. The addition of NaCl alone, or of KC1 and CaC^, is insuffi- 

 cient ;• but if all three salts are added in proper strength, life is made possible. 

 Loeb's theory of the action of the salts in such cases has been stated in connection 

 with the Echinoderms. 



Brunow ('11) in a biochemical study of the crayfish Astacus fluviatilis found 

 the loss in body weight proportional to the length of inanition, decreasing from 

 19.16 g. to 17.47 g. (loss of 8.8 per cent) in 70 days, and to 16.26 g. (loss of 15. 1 

 per cent) in 140 days. Morgulis ('23) found but 3 per cent decrease in the body 

 weight of the lobster (Homarus) after 56 days of starvation, and cites observa- 

 tions (by Moore and Herdman) showing no loss in weight after eight months 

 of fasting, the loss in dry substance being masked by absorption of water. 



Arachnida. — Lucas (1826) observed that the spider Epeira phalangoides 

 lived one and one-half months without food, while Haller noted a period of 

 several months for Epeira Walk. According to Lucas, De Geer found an 

 apparent increase in the weight of Epeira diodema kept one month without food 

 in 78 cubic inches of air. Treviranus gave 18 months as the starvation period 

 for Scorpio europaeus. Morgulis ('23) cites reports by Blackwell of 17 months 

 of starvation for spiders, and by Jacquet of 368 days for scorpions. 



Myriapoda. — Plateau ('78) observed circular constrictions of the intestine in 

 the Myriapod Julius starved 15 days. Childs ('21) starved Parajulus for 13- 

 42 days and obtained results somewhat resembling those of Needham ('97) on 

 dragon-fly nymphs. "Prolonged absence of food matter from the midgut of 

 Parajulus causes more or less irregular thickenings of the epithelium which give 

 the margin of the lumen a wavy contour and are attended by a reduction in the 

 thickness of the brush border. These thickenings are caused by the inhibition 



