252 BULLETIN OF THE BUREAU OP FISHERIES- 



THE WVER. 



The "liver" (pi. xxxiii and xxxiv), called also the gastric glands, hepatopancreas, 

 and by the chefs "tomally," is the largest single organ in the body. It is paired of a 

 green, bright yellow or yellowish green or yellowish brown color, and lies along the sides 

 and partly below the alimentary tract of which it is a part. 



The liver is a soft, lobulated mass, divisible on either side into three parts — a thick 

 anterior lobe, a long posterior lobe, and a less clearly marked dorsal or lateral lobe. 

 Each lobe is composed of many lobules, and each lobule of a multitude of short aggre- 

 gated tubes called the caeca. The lobules are covered by a delicate transparent mem- 

 brane, and when this is broken can be shaken out in water like tassels. 



A part of the secretions of the caeca is gathered by a system of converging tubes and 

 is finally admitted to the pyloric division of the grinding stomach, near the junction of 

 the latter with the intestine. These ducts also serve to admit streams of food particles 

 (see p. 249) to the glands themselves, where they are acted on by ferments and are directly 

 absorbed. 



THE KIDNEYS OR GREEN GLANDS. 



The direct excretion of nitrogenous waste products is effected by a pair of glands 

 which open at either side by a prominent papilla on the lower side of the basal segment 

 of the first pair of antennae. (PI. xxxin and fig. 6, pi. xxxv, g. gl.) In their funda- 

 mental relations these organs agree with the segmental nephridia of worms and 

 vertebrates. 



When unraveled, the entire organ has been found to consist of the following parts: 

 A large, thin-walled peripheral vesicle or bladder, and closely applied to this, in front 

 or below, the proper excretory organ or gland. Together these parts form a rounded or 

 flattened body of a light green color, closely fitting in the convex depression over the 

 articulation of the antenna on either hand and just in front of the stomach sac. 



The bladder empties to the outside by a short duct, the opening of which on the 

 papilla is guarded by a valve. The kidney proper is composed of a central saccule or 

 end sac, and of a convoluted tubule, both of which are glandular. According to Dahlgren 

 and Kepner (67) the tubule is lined throughout with nondliated epithelial cells, and 

 is covered by a tunic of connective tissue, it being in this section only that a cuticle 

 is secreted. Upon taking a lobster in hand a fine jet of liquid is sometimes thrown from 

 the papilla to a height of an inch or more. Inasmuch as water does not apparently have 

 access to the bladder, the walls of which are contractile, the liquid is probably a true 

 secretion. This fountain display of the green glands has been noticed but two or three 

 times. 



