164 Prof. M'Intosh's Notes from the 



In section of the body-wall the cuticle is said to occur only 

 on the anterior region, the epiderm alone being present 

 posteriorly. Moreover, Gilson thought no ccelomic epithe- 

 lium lined the muscles internally, a view opposed by Drasche 

 and Ogneff *. 



There are six, sometimes seven f, pairs of cylindrical, rigid, 

 thread-secreting glands of considerable size, which hang 

 loosely in the body- cavity — a pair to each of the 1st and 2nd 

 anterior segments, and the first four posterior segments. Each 

 is attached to the body-wall by one extremity, which forms a 

 duct opening between the end of the torus and the bundle 

 of setse of the segment to which it pertains (Watson). 

 These secrete a thick viscous liquid containing fine colourless 

 threads used in the formation of the inner lining of its tube. 

 De St. Joseph found a minute distome fixed to one of the 

 glands. 



The septa, as pointed out by Gilson, have two valves, viz., 

 a simple slit or flap-valve dorsally opening forward like a 

 door and a sphincter valve ventrally. Watson noticed that 

 the forward current passed through the dorsal valves, and the 

 backward current of ccelomic fluid through the ventral. 

 These valves are specially powerful in the septum separating 

 the anterior from the posterior region. 



The next three segments are comparatively long, each 

 being about twice the length of the anterior region of three 

 segments. The firet of these (the 4th bristled segment) has 

 two dorsal bristle-tufts immediately behind its anterior 

 border, and two tori for hooks ventrally in the same line as 

 the bristle-tufts. Two dorsal glandular bands pass laterally 

 from the bristle-tufts to those of the succeeding segment, 

 curving inward as they approach the latter. The ventral 

 surface is marked only by the median band. The next two 

 segments follow the same arrangement dorsally and ventrally. 

 Watson describes an olive-green zigzag canal as running 

 almost from end to end of the second segment of the posterior 

 region, and this is the nephridium of Gilson, for it has an 

 internal funnel-shaped opening and a slit-like aperture 

 externally. He found, however, that it does not transmit 

 the genital products as Gilson supposed. The seventh 

 bristled segment is shorter, but it also presents the same 

 glandular bands dorsally, the dorsal bristles in front of this 



* " Au-dessous de la cuticle, de l'hypoderme et de la couche des muscles 

 circulairea qui n'existe que dans le thorax l'enveloppe du corps est 

 tapissde d'une couche continue de muscles longitudinaux," etc. 



t Gilson indicates a rudimentary gland in the 3rd anterior segment. 

 It is sometimes absent. 



