MANTLE-GLANDS OF CHROMODORIS. 



109 



development of the glands. If these inferences be correct, an 

 interesting parallel is afforded with a law of regenerative phe- 

 nomena in plants (cf. Loeb, '15; 'iSa; 'iSfr). 



II. 



The outline oi the caudal veil is characteristically smooth and 

 approximately semicircular. In a certain number of cases, how- 

 ever, there are apparent in this outline obvious irregularities of 

 a secondary nature. Among the individuals presenting a regular, 



FIG. i. A. Chromodoris zebra, caudal veil (c) turned up so as to show the 

 glands (black dots) on its ventral surface ; a, buccal veil ; b, branchial collar, 

 contracted over the concealed branchiae; in, mantle folds; o, oral tentacle; p, 

 reproductive papilla; r, " rhinophore " ; t, "tail" of the foot (X 3 A)- 



B. The caudal veil in ventral aspect, " tail " part of foot turned to one side; 

 this shows a plan of distribution that, on the whole, is the most common. 



unindented margin, the number of glands varies from I to 16 

 (Fig. 2). The most common arrangement of the glands is, that 

 one is median, with two on either side of it, all evenly spaced 

 (Fig. i, J5). Typically, the five glands in such a set are of about 

 the same size, although in many cases the median gland is the 

 largest. 



Although five is the modal number of glands (Fig. 2), other 

 numbers are common ; some of these arrangements are illustrated 

 in Fig. 3. Not infrequently one or another gland in an other- 



