OF POLYPI. 179 



doubling they are so crowded as to render even the counting 

 of them not a little troublesome, to say nothing of defining the 

 exact relations of each one to its fellows. But I need not so 



O 



beyond this point, however, as sufficient has been said to show 

 how this method of increase is carried out. 



I will merely reassert what I have already said, now that you 

 are more familiar with the organization, that these successive 

 alternations of the series, one, two, three, four, &c., of tentacles 

 and their corresponding partitions, always have a direct reference 

 to the right and left sides of the body. This you rnay recognize 



in the diagram (fig. ^^^^ma^^m^&sai 

 108) of the successive 

 productions of the par- 



501 



titions, much more 



clearly than could be 



seen in the crowded 



disc of an equal num- 



ber of tentacles. If 



you attempt to divide 3rt ! 



the body into equal le l 



halves by running a 5al 



line through any other 



two opposite points 3 i 



than those which lie in 



the prolonged vertical plane of the flat stomach, (I, II,) you will 



Fig. 108. Cereus Sol. Verrill. 2 diam. From Charleston, S. C. A fore- 

 shortened view of the interior, from just behind the mouth, backwards to a point 

 a little behind the posterior end of the stomach (I, II). rf, the general digestive 

 cavity ; Z, spaces between the pairs of partitions, the arrows indicating the pas- 

 sage-ways to and from the general cavity (rf) ; p, />!, the two partitions of one of 

 the largest pairs ; m, the muscular layer on the opposite faces of p, p 1 ; *, f, the 

 reproductive organs, which in profile (fig. 28) appear like a deep frill along the 

 edges of the partitions, extending from the posterior end (fig. 28, P) of the body 

 toward the head ; I, II, the two plicated, upper and lower, edges of the flat 

 stomach; 1, la, 16, Ic, Id, le, the six pairs of the first set of partitions; 2, 2a, 

 26, 2c, 2f/, 2e, the six pairs of the second set ; 3, 3a, 36, &c., the twelve pairs of 

 the third set; 4, 4a, &c., the twenty-four pail's of the fourth set; 5, 5a, 56, &c.. 

 the forty-eight pairs of the fifth set. Original. 



