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SCIENCE 



[N. S. Vol. XXV. No. 632 



dropped the cast and grasped the female 

 between the abdomen and thorax, and, moving 

 around from the dorsal surface of the female, 

 deposited the spermatophore in its place upon 

 the genital segment. He then freed the 

 female and made no attempt to renew his 

 hold. In six days the female produced eggs 

 which hatched in seven days. 



Despite a gi-eat deal of effort, we have never 

 again been able to observe the molt and sub- 

 sequent copulation, but we have complete evi- 

 dence that, in three species of two genera 

 (Earpacticus iiniremis, E. gracilis and Tachi- 

 dius littoralis), the spermatophore is never 

 attached before the female molts, and that, in 

 every case, the male holds the female until 

 she molts. Whenever a normal pair, left a 

 short time before in copula, were found sepa- 

 rated, careful examination revealed the cast 

 of the female in the watch glass and a sper- 

 matophore attached to the female. In other 

 words, every successful copulation must be 

 prolonged until the female molts. 



The longest period in copula observed with 

 a successful issue was between twenty-nine 

 and thirty-nine hours. In two cases the 

 female died in molt, an antenna and a furcal 

 bristle respectively being caught in the cast. 

 In several instances the male, the female, or 

 both died before the molt, probably because 

 of the abnormal conditions of the experi- 

 ments. In one case the male of a copulating 

 pair was killed and, after the female had 

 molted, another male was introduced, but no 

 copulation took place. 



These observations are by no means the 

 first of this character, for there is a general 

 impression among students of Crustacea that 

 ecdysis and copulation or ovulation are closely 

 connected processes. There is evidence that 

 copulation follows a molt of the female in 

 several crabs" and in the isopod Gnathia.' 



' See Herriek, F. H., ' American Lobster,' Fish, 

 Comm. Bull., 1895, p. 39. Williamson, H. C, 

 ' Contributions to the Life History of the Edible 

 Crab, Cancer pagurus,' Rep. Fish. Board, Scotland, 

 v., 22, 1904. Barnes, E. W., 'Natural History 

 of the Paddler Crab, Callinectes hastatus,' 34th 

 Report Comm. Inland Fisheries of Rhode Island, 

 p. 69, 1904. 



' Smitli, G., ' Metamorphosis and Life History 

 of Qnathia maxillaris,' Mitt. Zool. St. Neapel, 

 XVI., pp. 469-471, 1904. 



There is also evidence that ovulation follows 

 the molt in some isopods and amphipods.* 

 Finally, Delia Valle" finds that the male of 

 Gammarus pungens holds the female until she 

 molts, assists in freeing her from the cast, and 

 then deposits the sperm. 



The males of Amphipoda, Isopoda, Artemia 

 and related Phyllopoda, Limulus, and of the 

 Copepoda of the group under discussion all 

 have the same habit of carrying or holding 

 the female and all have structures modified 

 for this purpose. Hence, it is possible — it 

 is even probable — that this habit and these 

 structures indicate that, in these forms, the 

 female must molt before fertilization can be 

 accomplished. 



Our attempts to find the meaning of this 

 presumably general habit of the Crustacea 

 mentioned have been unsuccessful, but we be- 

 lieve that the softened condition of the shell 

 may be necessary for the attachment of the 

 spermatophore or the extrusion of the eggs. 

 Leonard W. Williams 



blowing springs and wells of georgli, with 

 an explanation op the phenomena ' 



The blowing springs and wells of Georgia 

 may be divided, for convenience of descrip- 

 tion, into two classes, namely, those in which 

 the air passes inward for a time and after a 

 short period of quiescence reverses its course, 

 and those in which the quantity of the air is 

 constant and moves in one direction only. 

 One of the best illustrations of the former 

 class of springs is the Grant Blowing Spring, 

 near Chattanooga, Tennessee, a description of 

 which is as follows : 



The Grant Blowing Spring is located at the 

 base of Lookout Mountain near the Georgia- 

 Tennessee state line about three miles from 

 the corporate limits of Chattanooga. The 



* Langenbeek, C, ' Formation of the Germ 

 Layers in the Amphipod Microdentopus gryllo- 

 talpa,' Jour. Morphology, XIV., p. 303. See also 

 Korschelt & Heider, ' Text-book of Embryology ' 

 (English translation). Vol. II., p. 105. 



' Delia Valle, A., ' Gammarini del Golfes von 

 Napoli,' Fauna and flora des golfes von Neapel, 

 20, p. 276, 1893. 



' By permission of the state geologist. 



