Literary Notices. 285 



In discussing the law of biogenesis and the significance of rudi- 

 mentary organs Eigexmann points out that the eye is not retained by 

 the embryo Amblyopsis because it is a functional organ at this stage, 

 since during cave life the eyes are as useless to the young as to the 

 adult. c. w. p. 



Linville, Henry R. The Natural History of Some Tube-forming Annelids 

 (Amphitrite ornata, Diopatra cuprea). Art. XI, pp. 227-235. 



This paper gives a description of the tube-forming activities of 

 the two annelids named in the title. Amphitrite constructs a U-shaped 

 tube of mud and sand collected liy the tentacles and held in place bv 

 mucus. The tube l^egins as a ring immediately behind the bases of 

 the tentacles and the gills, and as the process of building is continued 

 this ring is pushed backward by muscular action to make room for the 

 materials which are brought by the tentacles. The author calls atten- 

 tion to the curious fact that this aunelid is unable to reconstruct a new 

 tube after the whole of its original tube has been removed. This he 

 thinks, is due possibly to the absence of a stimulus from the tube which 

 ordinarily initiates tube-repairing activities. The worm when young 

 possesses an instinct which determines the construction of a tube, but 

 this instinct after the formation of the first tube becomes valueless 

 and disappears, hence when the animal is stripped of its tube it is un- 

 able to begin a new one. The presence of even a small portion of the 

 old tube, however, is sufficient to initiate the appropriate tube-building 

 actions. 



Diopatra constructs a tube of sand, pebbles, bits of glass or any 

 other material within reach. According to the observations of Dr. 

 LiNviLLE, it gives no evidence of selection of materials. The particles 

 gathered are glued together with mucus secreted by the ventral glands. 

 The animal first places a few pebbles in position then rubs the glands 

 over them until they are firmly cemented. If, during the gluing 

 process, the tentacles be touched with a piece of stone the process at 

 once ceases, and the animal begins to gather material again. Thus 

 the tactile stmiulus determines the activity. The author mentions 

 several interesting observations in connection with food taking and 

 respiration. r. m. v. 



Neal, H. V. The Development of the Ventral Xerves in Selachii. I, Spinal 

 X'entral Nerves, Art. X^', pp. 291-313. 



While this research by no means clears up definitely the much 

 discussed question of the hi.stogenesis of the peripheral nerves, it nev- 

 ertheless is a useful contribution and will serve to deter manv from ac. 



