SKCTION OF NAKKD-EYED MEDUSAE 



117 



of the latter is rendered pussible, other coiineetions 

 between these or^^ans remain wliich are not in any 

 wi.se radial. 1 therefore next tested the degree in 

 which these non-radial connections might be cut 

 without causing destruction of that excitational 

 continuity of a lower order which it is their func- 

 tion to maintain. It will here suffice to record one 

 mode of section Avhich has yielded definite results. 

 A glance at the accompanying illustration (Fig. 23) 

 will show the manner in which the Medusa is pre- 



Fig 23. 



pared. The margin having been removed (in order to 

 prevent possible conduction by the marginal nerve- 

 fibres), a single deep radial cut (a a) is first made, and 

 then a circumferential cut (a, h, c) is carried nearly 

 all the way round the base of the manubrium. In 

 this way the nectocalyx, deprived of its margin, is 

 converted into a continuous band of tissue, one of 

 the ends of which supports the manubrium. Now 

 it is obvious that this mode of section must be very 

 trying to nervous connections of any kind subsist- 



