DESICCATION IN PHILODINA ROSEOLA. 367 



moisture the cuticle could form a rigid capsule which would 

 retain the original shape of the folded animal even if the muscles 

 did relax. 



On the other hand it would seem that if the maintenance of 

 the shape of the folded animal w r as due to the action of the 

 cuticle the muscles would be somewhat flattened in cross-section 

 as a result of the mutual pressure of internal organs and integu- 

 ment. This last condition, however, is not true, for the muscles 

 in the dried animal still show in cross-section something of their 

 oval outline. It seems probable that there is a limit to the 

 amount of drying which a muscle may undergo and at the same 

 time continue to exert a contractile tension. But the amount 

 of drying necessary to cause a muscle to reach this limit would 

 at the same time withdraw enough water from the cuticle to 

 cause it to become rigid. I think, therefore, that we can account 

 for the lack of relaxation at the time of drying by assuming that 

 both of the factors mentioned above acting in succession produce 

 the given result. 



The appearance of the mastax and its surrounding salivary 

 glands in the dried animal is shown in the central part of Fig. 16, 

 but perhaps better in Fig. 25. Upon comparison with Fig. 24, 

 which is a section of the undried mastax and glands, it will be 

 seen that the entire structure has collapsed and decreased per- 

 ceptibly in size. The gland tissue is more dense as to its cyto- 

 plasmic content while the nuclei, although just as prominent as 

 before, show the same rearrangement of chromatic material as 

 was described for the nuclei of other tissues in an earlier para- 

 graph. The details of this chromatic movement given for the 

 nuclei of the vitellarium and ovary will apply here and need not 

 be repeated. The same is true of the foot-gland cells although 

 I have observed certain cases where the nuclei of the latter do 

 not assume the usual ring form. This condition is shown in 

 Fig. 19. 



The stomach of the dried animal shows, perhaps, the most 

 remarkable changes. In Fig. 16, lying below and at the side of 

 the mastax, is figured the stomach in its dried condition. The 

 cytoplasmic syncytium still preserves its alveolar appearance. 

 The lumen is shown winding about through the syncytium, while 



