56 



Glands of Deshayes. - Closely associated with the ciUs 

 or the adult is a pair of very complicated structures 

 v/hicli, so far as known, are peculiar to Teredo , and 

 which constitute one of the most important features wliich 

 distinr:uish the "Ship-v;onns"from other types of Lamelli- 

 branchs. In honor of the observer who first described 

 them, I have called them the glands of Deshayes. Though 

 he pointed them out, they have never boen fully described 

 as to character, structure and relations. 



Deshayes observed a peculiar structure in the umbo- 

 nal region oh either side of the shell cavity. Ke describ- 

 ed it as of glandular nature, and supposed its function to 

 be the secretion of a fluid to soften v/ood in the forma- 

 tion of the burrov/. - In the gill laminae he described pe- 

 culiar modifications of the tissues, which he supposed to 

 be mucous glands, and to serve for the nutrition of the 

 viviparous embryos of Teredo. He also described a third 

 structLire, as invading a part of the walls of the afferent 

 brancheial vein, and of unkno-^m function. These three 

 glands described by Deshayes are parts of one and the same 

 structure which is present, in different degree of devel- 

 opment, in all of tlie three species I have studied. In 

 all three the part in the gill is well developed. In T. 



