70 



THE ORGANIZATION OF 



of worm-shaped bodies which lie within the digestive cavity, at 

 four points opposite, and close to, the four sides of the base of 

 the proboscis (m). 



It is not necessary for present purposes that I should go any 

 further with you into the history of the development of the 

 Ephyra; but I will, at any rate, indicate what is the final result 

 of that process, in order that you may see to what extremes of 

 difference the two kinds of individuals of Aurelia arrive. 



c ^ < 8 < 7 I have repre- 



sented here (fig. 

 37) an Aurelia 

 in extreme old 

 age, when its 

 disc measured 

 ten inches in 

 diameter. At 

 first you will 

 have some dif- 

 ficulty in recog- 

 nizing the parts 

 which corre- 

 spond to those 

 in the Ephyra, 

 which I have 



just described; yet I think a word or two of explanation will 

 make their relations clear to your eyes. In the first place I must 



Fig. 37. Aurelia flavidula. Per. and Les. Natural size, 10 inches in diame- 

 ter. The common " Sunfish" or " Sting-blubber" of the Atlantic coast, in its 

 old age, when all of the digestive canals, both straight and branching, are united 

 with each other. A view from the side opposite to the mouth, the whole internal 

 organization appearing through the thickness of the gelatinous umbrella. The 

 proboscis has four lance-shaped arms, here represented by the winding, dotted 

 line, forming a cross, which extends to the edge of the umbrella, on the right 

 and left and above and below, m, the central digestive cavity ; ch, the four prin- 

 cipal digestive canals ; t 1 , < 3 , t 5 , I 5 , the four secondary digestive channels ; t, ft, 

 <4, i 6 , &c., the eight digestive canals of the third set, at the points where they 

 join the circular marginal canal, 7 ; an, the points of junction, or anastomosis, 



