210 CARNEGIE INSTITUTION OF WASHINGTON. 



tion of growth of the polyps and does not cause an abnormal growth of tissue 

 by mechanical or chemical stimuli, such as occurs in the plant galls inhabited 

 by insects. 



A Note on the Hermit Crab, PAGtrRus deformis. 



It has long been known that the male of this species possessed, besides the 

 normal pair of reproductive apertures on the last pair of walking legs, an addi- 

 tional pair in the position usually occupied by the female apertures. It was 

 regarded as important to see whether other indications of hermaphroditism 

 were to be found in the male, especially in view of the secondary hermaphro- 

 ditism which occurs in some male hermit crabs which are infected by rhizo- 

 cephalan parasites. 



The species was not abundant at Murray Island, but the individuals col- 

 lected showed plainly that the males and females are easily distinguishable 

 from one another and that true hermaphroditism does not occur. Though 

 the male invariably possessed supplementary apertures, the corresponding 

 ducts and glands have not been observed and the swimmerets are never of 

 the female type. Nor does the testis show any signs of hermaphroditism, 

 though I have jTt to cut sections of these. 



No male characters are developed in the female and it is evident that we 

 have here a curious case of the inheritance by one sex of a single secondary 

 sexual character belonging to the other, such as occurs in the female reindeer, 

 which has horns like the male. 



Re-port upon the Behavior of the Dimorphic Spermatozoa of Strombus, 



by Edwin E. Reinke. 



The investigation carried on this year at Tortugas is a direct continuation 

 of the work which was accomplished and reported on last year. Although no 

 definite general conclusions have been reached as yet, it would be well to make 

 a statement of the problem as it presents itself to the writer, and to describe 

 the methods used in attacking it, together with a brief outline of the results 

 obtained so far. 



The writer has shown^ that, in their development, the atypical or apyrene 

 spermatozoa lose their nuclei and every trace of chromatin disappears from the 

 cell. Hand in hand with the loss of chromatin proceeds the formation of 

 secreted bodies which eventually fill the entire cell. Two undulating mem- 

 branes, which are developed on both sides of the cell-body, provide the 

 apyrene spermatozoon with a high degree of motility. The development of 

 the typical or eupyrene spermatozoon corresponds in its essentials to that 

 which has been described for the eupyrene spermatozoon of other Proso- 

 branchs.'^ 



The view has been expressed by the writer that the apyrene spermatozoa of 

 Strombus are accessory cells of the testis and are not spermatozoa in the true 

 (physiological) sense of the word. An examination of a number of females 

 which had undergone copulation showed several things very clearly. In the 

 first place, the apyrene spermatozoa found in recent ejaculates are in the same 

 condition as when found in the sperm-ducts; that is, the undulating mem- 

 branes and the secreted bodies are intact and the cells become activated when 

 mixed with sea-water. Second, a sharp separation of the two kinds of sperma- 



'Papers from the Tortugas Laboratory of the Carnegie Institution of Washington, vol. 6, 1914. 

 *See Meves. Fr. Arch, fur Mikr. Anat. Bd. 61,1903. Also: Kuschakewitsch, S. Arch, fiir 

 Zellforsch., Bd. 10, 1913. 



