436 



MULTIPLE OUTLETS IN THE DEMANIAN SYSTEM 



does it seem that the multiple outlet would have anything to do with the 

 quality of the secretion that is prepared. The most reasonable supposition 

 is that, in use, the demanian secretion is rendered more effective through a 

 multiple delivery, and it is not difficult to reason out why this might be so. 



Take, as a basis of reasoning, the fact that spiders have multiple spinneret 

 tubes. This plurality is an advantage in that if some tubes of the spinneret 

 apparatus do not act, or are restrained from acting, the remaining ones may 

 continue to act, an economy of a kind often seen in nature. Thus threads 

 of varying size and composition can be "spun." It seems not unlikely 

 that the multiple thread of the spider may have 

 dnldsf. effdlt fsc structural advantages; at any rate it is a fact that, 

 in some cases at least, the thread can be artificially 

 split into components harmonizing in number 

 with the elements of the spinneret apparatus. 

 If these be advantages, it is quite conceivable that 

 *** they may apply in some way to the multiporous 

 Adoncholaimus panicus, and this would harmonize 

 with the previous conclusions concerning the 

 function of the demanian system; for presum- 

 ably the secretion in panicus is like that of other 

 oncholaims, i.e. a copious, sticky, non-water- 

 soluble, elastic material; at least these arc its 

 properties after it is delivered into sea water by 

 pristiurus. 



The location of the outlets of the demanian 

 system is always well caudad, and the oncholaims 

 having the system are agile and limber, all of which 

 harmonizes with the belief that the system elabor- 

 ates material used with some degree of "skill." 

 Fig. 7. Adoncnolaimus . , , . , ., , 



panicus n.sp. Side, ven- All oncholaims having the demanian system 

 tral and sectional views of have a habit of coiling and uncoiling and can with 

 the posterior portion of the , ij.i-i r,i 



same female, eff prep, the the greatest ease place the exit pores of the system 

 principal efferent at the against any part of the body except the tail and 

 point where it forks to pro- ... ,. , . . ., , ,, . , , ., , , , 



duce the two deltic effer- its immediate vicinity, and this habit, no doubt, 

 ents, eff dlt; the seven-fold j s correlated with the function of the secretion, 

 delta is shown at delta and _. . , , i i . 7 7.77 



the seven exit pores at exit. Females of such oncholaims have relatively short 



tails, as if longer ones would perhaps be in the way. 



Conceivably, of course, the demanian secretion might have properties 

 attractive to the other sex (odor, etc.), but the idea does not seem to appeal 

 so strongly as that of having something to do with other matters. 



In this connection it may be recalled that, opposite the demanian exit 

 pores of Metoncholaimus albidus (Bastian), deMan described and figured a 

 persistent girdle of left-over yellowish brown secretion. 



