THE AMERICAN LOBSTER. 131 



of these "olfactory buds," their cuticular canal, gland-like cells, and large eccentric, 

 in this case multipolar, ganglion, prove conclusively that these organs are essentially 

 similar to the glands which I have described in the lobster. In discussing this subject 

 with Professor Patten we have always been mutually agreed upon this point. What 

 the function of these organs in all cases really is, may well be an open question. In 

 Limulus the lumen of the organ varied much in appearance, being more sharply 

 circumscribed in the young than in the adult, where it might be reduced or even absent. 

 The tubule was sometimes coiled and very brittle. It is "undoubtedly composed of 

 cliitin, for, as with the gustatory tubules, it can still be seen in the cast-off shells of 

 immature specimens and in the fresh shells cleaned with potash." The same is true 

 of the cuticular canals of the glands of the lobster, except that the tubule is always 

 apparently straight and is never effaced. 



Lang {114) mentions some of the many cases in which glands have been described 

 in the body and appendages of various Crustacea, attributing to some of these "der- 

 mal" structures an excretory function, a fact which, he says, may be proved by feeding 

 with carmine. 



Unicellular glands of a remarkable character have been described in the append 

 ages of various amphipods by Nebenski (140), Clans, and others. Here they are found 

 in both sexes, but are confined in Orchestia to terrestrial species. Nebenski thinks that 

 in the latter they may serve a respiratory function by keeping the gills moist. 



The glands situated in the mouth parts, when stained in Ehrlich-Biondi anilin 

 mixture, select the green with more regularity, the nuclei taking up the red. This, 

 however, maybe due to slightly different methods of treatment in washing out the stain. 



The differences between what appear to be the resting and active gland, illustrated 

 in figs. 212, 211, which are fairly characteristic of the swimmerets, immediately before 

 and after ovulation, respectively, should not be given undue importance, since these 

 conditions are met with, though less commonly, in other parts of the body. 



Micro-chemical reactions point clearly to the glandular nature of the large periph- 

 eral cells of which these organs in certain places are composed. It is probable that 

 in the pleopods they are concerned with the secretion of cement, for the reasons 

 already given. What, then, is the function of the eccentric bipolar cell 1 ? Is it a reflex 

 center for the gland, or is this a sensory cell which conveys impulses received from 

 without to a reflex center in the central nervous system governing the secretory 

 activity of the glandular cells? If the former supposition were correct, another ques- 

 tion would remain to be answered: What are the organs of the sense of taste? The 

 remarkably quick responses which are obtained upon stimulating the mouth parts 

 immediately suggest the presence of gustatory organs. Such animals as the lobster 

 and crab undoubtedly possess the sense of taste, but no organs have yet been 

 described to which this function could be ascribed. Huxley says : 



It is probable that the crayfish possesses something analogous to taste, and a very likely seat for 

 the organ of this function is in the upper lip and the metastoma; but if theorgan exists it possesses no 

 structural peculiarities by which it can be identified. 



The labrum of the crayfish, so far as I could ascertain from a single specimen 

 which I sectioned, contains no such glandular organs as occur in the lobster. 



If it is inadmissible to regard any of the tegumental "glands" as gustatory 

 organs, we must conclude that no distinct organs of taste can be detected in this 

 animal, which has the power of discriminating its food. Is it possible, as Lemoine 

 suggested (118), that the sense of taste is in some species blended with that of smell 



