BAUMGARTNER: OBSERVATIONS ON THE GRYLLID^. 315 

 PROTECTIVE GLANDS IN THE MOLE CRICKETS. 



As indicated in an abstract (4), I have found that the correct 

 interpretation of the function of the anal gland, which has so 

 long puzzled investigators, is protective. Leon Dufour (8), a 

 careful French investigator, first described in the mole crickets 

 in both sexes a pair of azure or skim-milk colored glands con- 

 nected with the rectum. Their secretion he compares in con- 

 sistency with the vitreous humor of the human eye. To this 

 secretion is added some excrement from the rectum, and when 

 this mixture is expelled it forms a brown liquid of nauseating 

 fetidity. He calls the gland "an organ of excremental se- 

 cretion." 



Berlese (5) describes the same structure and thinks it is a 

 prostatic gland analogous to that found in the locustids. Al- 

 though he found it in the female also, he does not seem to try 

 to explain it there. 



Fenard quotes both of the above descriptions and adds a good 

 many observations of his own. He describes the gland from 

 sections and gives the action of certain fixatives and stains 

 upon the tissues of the gland and its contents. He states in 

 detail the macroscopic and microscopic structure. He concludes 

 as follows : "Judging from the position of this organ, from the 

 consistency of the liquid which it contains, and from its points 

 of similarity with the prostatic glands of the locustids, I think 

 that it ought to be considered also as a gland furnishing a 

 mucus destined to lubricate the copulating apparatus. This 

 organ exists in the female, it is true, but in this case it fur- 

 nishes without doubt still a lubricant for the vagina, or a 

 liquid to form the nest of these insects." After describing the 

 details of this gland in the female he says : "I think that these 

 organs can only be some secreting agent of a mucus destined 

 to lubricate the genital organs ; or perhaps they glue together 

 and hold the spermatophores ; or perhaps again they secrete 

 the substance used to form the nests in which are found, as 

 we all know, two to three hundred eggs all massed together 

 and more or less united." It is evident from this uncertainty 

 that Fenard did not know the function of the glands in ques- 

 tion, yet he was inclined to follow Berlese and called them 

 "prostatic glands." 



Packard, in his work on Entomology, places the anal odor- 

 iferous glands described by Dufour among the repugnatorial 



2-Univ. Sci. Bull . Vol. V, No. 18. 



