2 Mr. R. Vallentin on the 



The Tube. — The tube or case in which the animal usually 

 dwells consists of a jelly-like material, extending from the 

 collar to the extremity of the foot. Into this, when the 

 necessity arises, the animal can retire. It is formed by the 

 young Rotifer soon after its exit from the parent's tube ; 

 but whence it originates has hitherto escaped observation. 

 Mr. Jackson (2) says " Some few Rotifera develop round 

 themselves a gelatinous case, which they inhabit perma- 

 nently (Floscularia) or temporarily (Philodina), the origin of 

 which is unknown." Dr. Hudson (loc. cit.) says, " Neither 

 salivary, gastric, nor foot-glands have been observed in 

 Stephanoceros ; but ? as the animal secretes a large and com- 

 paratively solid tube, it is clear it must have some organ for 

 this purpose or that the substance of which the tube is con- 

 structed oozes from the surface of the body." The most 

 important observer is Mr. Gosse (loc. cit.). He says, "A 

 specimen, which was hatched under my eye, swam for ten 

 minutes, and then became permanently attached to the upper 

 glass of the box, so that it was vertical in position, with the 

 foot next the eye, a favourable aspect for observing the 

 development of the case. It presently began to dilate its 

 body, and, in about five minutes from its attachment, I per- 

 ceived a distinct filmy ring round it, perfectly circular, whose 

 diameter was about twice that of the body. The little animal 

 now began to lean over to one side, and the ring soon had 

 another segment additional, leaning in the same direction. 

 The case, for such it was, looked like two broad hoops of 

 glass, each swollen in the middle and set one on the other, 

 but not quite concentrically, at least to the eye of the observer. 

 It was manifest that it was produced from an excretion from 

 the body, owing its form and size to the animal's moving- 

 round on the foot as on a pivot." 



It has been a fact familiar for many years to zoologists 

 that many of the migratory Rotifera possess in the foot 

 glandular bodies, the secretion from which enabled them to 

 fix themselves for a long or short period to any substance. 



Dr. Zacharias (3), in his paper on Rotifer vulgaris, says, 

 " We know that they [pedal glands] are the seat of a secre- 

 tory activity, and secrete a sticky product which serves to 

 attach the animal to smooth surfaces." 



Eckstein (4) gives a description of glands in the foot of 

 Floscularia, and says, " Der Fuss, welcher von einer faltigen 

 Haut bekleidet ist, endigt in zwei sehrkleinen Spitzen,zwischen 

 denen eine etwas langere Rohre hervorragt." He gives a 

 figure of the glands as seen in optical longitudinal section. 



With regard to Stephanoceros : it seems on the face of 



