768 RECORD OF CURRENT RESEARCHES RELATING TO 



a single orifice. It is made up of a certain number of completely- 

 separated glands, while each has a special duct which opens directly 

 into the stomach. These ducts and the lobes of the glands do, how- 

 ever, become somewhat entangled, and thus give rise to the appearance 

 of a single compact mass, by which the subdivision of the organ is at 

 first sight obscured. Ten distinct lobes may be generally made out. 

 The ultimate cells are large, polymorphous, and variously coloured ; 

 they contain vesicles which may. either be scattered through the cell 

 or aggregated into a small central mass ; they vary in coloui- through 

 different shades of yellow. 



The author applies the term independent glands to certain distinct 

 structures ; these are (1) Circumoral glands and (2) posterior gland of 

 the foot. The former are found in the integument around the orifice 

 of the proboscis, and within the first cavity of the body ; they vary a 

 good deal in form, but always end in an excretory duct, which opens 

 at the entrance to the orifice of the proboscis. Their contents are 

 hyaline, and are made up of nucleated vesicles with a nucleolus, and 

 granular bodies suspended in a colourless liquid. They are not, as 

 the author first thought, unicellular glands, notwithstanding the sim- 

 plicity of their structure. Their function appears to be that of 

 assisting in the prehension of the microscopic organisms which form 

 the food of these creatures. 



The posterior gland of the foot appears to have escaped notice 

 altogether ; this is the more remarkable since it is visible to the naked 

 eye. In general constitution this gland has much the same structure 

 as those around the mouth ; its secretion is in the form of a rich supply 

 of mucus, which seems to form a kind of raft for the animal, and 

 thereby to enable it to float on the surface of the sea. 



The organ of Bojanus is of some size, is placed on the right 

 side of the body, is of an ochreous yellow tint, and somewhat trans- 

 lucent. Spongy in constitution, its cell-elements are spherical in 

 form, and among their contents it was not possible to detect any 

 crystals of uric acid. On its external wall there is, in front of the 

 anus, a constant black spot ; this, on careful examination, was seen to 

 have in its centre five or six small orifices, by means of which the 

 gland communicates with the exterior. The walls of the gland are, 

 as is usual, richly supplied with veins. 



Bed Gland. — This gland, the presence of which the most super- 

 ficial observer cannot fail to detect, extends over a portion of the 

 intestine and over the walls of the " copulatory pouch." Its con- 

 stituent cells, though smaller, are not unlike in character to those of 

 the organ of Bojanus ; the contained granular bodies are greyish or of 

 a bright red, and disappear altogether under the action of acids. The 

 author is forced to content himself and his readers with an account of 

 the structural characters of the body, as he is unable to offer any definite 

 suggestion as to what its function may be. 



Bespiratory and Circulatory Organs. — These must be dealt with 

 very briefly ; the former consists of a semi-pinnate branchial plume, 

 made up of a number of lamellae, more or less free at their extremity, 

 and invested by an excessively delicate tissue. The external orifice 



