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THE AMERICAN NATURALIST 



[Vol. LV 



abdomen. All these point to normal development as the rational 

 explanation. 



He figures, p. 226, the abdomens of five female ''intersexes," 

 including, I think, but am not sure, two abdomens of successive, 

 or near successive molts in the aquarium. As no two of these 

 abdomens are of the same width, the illustrations would indicate 

 a change in size of body, that is, growth and surely age, with 

 the molt or molts. But Professor Morgan says, p. 225, lines 

 13-14, "that the condition of the abdomen and claws had not 

 changed." 



The fact of the matter is, that neither Professor Morgan nor 

 any one else, so far as I know, is aware of the exact growth 

 changes of our fiddler crabs beyond the first few crab stages. 

 Hyman, in '.'The Development of Gelasimus after Hatching, "^ 

 carries his painstaking researches only as far as a 4 mm. wide 

 crab stage. 



We can at present reason only by analogy from the study of 

 work done on other species of crabs, of which there is altogether 

 too little compared to the facilities offered by the laboratories 

 of our coasts ; and such analogy seems to indicate that the crabs 

 upon which Professor Morgan bases his arguments are normal 

 females which had not, in their particular cases, attained sexual 

 maturity. Churchill's "Life History of the Blue Crab"-^ may 

 be cited, and also Pearson's "Cancer. (The Edible Crab.)"* 

 Both of these give tables which demonstrate the great variability 

 in the ratio of increase at each act of eedysis. 



It is important, as I have stated olscwhon'. rliat the develop- 

 ment of each of our common crabs be can-ipd thn)u^h from the 

 egg to maturity, that accurate records 1)e luade, and properly 

 labeled material upon which such studies are based be deposited 

 in an enduring collection accessible to all who may be interested. 



Mary J. Ratiibttx 



VARIATFOX IX JT'VEXILE FIDDLER CRABS 

 It is too bad tliat :\riss Rathlnm 's 'kindness in sending me 

 specimens fi-oni tlio Xational Museum "had the opposite effect 

 from that intended." While regretting this, I can only call 

 attention to the fact, stated in my pap.T, tliat out of more than 



2 Jour. Morphol., Vol. 33, No. 2, March, 1920. 



3 Bull. Bur. Fisheries, XXXVI, Noveml>€r 11, 1919. 

 *Proc. and Trans. Liverpool Biol. Soc, Vol. XXII, 1908. 



