113 



branches may usually be observed in all stages of development. Be- 

 sides the dissepiments at the origin of each lateral branch of the ra- 

 dical tubes, the latter, especially towards their extremity, present 

 transverse septa, and thus exhibit, in their mode of growth, a close 

 resemblance to many Confervas. 



It will be difficult to make the more complicated conformation of 

 the celliferous portion clear without reference to the figures. 



The celliferous branches which constitute the principal part of the 

 whole polypidom, arise, as has been said, either immediately from the 

 discoid central body of the root, or from the radiating radical tubes or 

 their lateral branches. They vary infinitely in number in different 

 individuals, and differ also extremely in length, — some being nearly an 

 inch long, but in the majority of individuals they are about half an 

 inch in length when laid straight. When the zoophyte is living or 

 recent, and unaltered by the fluid in which it may have been placed, 

 the celliferous branches are always much curled, reminding one in 

 their habit, thence derived, of the vernation of the fronds of many 

 ferns, and the whole zoophyte from this acquires a peculiar and very 

 elegant aspect. The branches divide dichotomously at tolerably re- 

 gular intervals. They support the bracket-like polypiferous cells, 

 which are placed in pairs, and with extreme regularity. It is to be 

 observed, however, that at the bottom of every branch or at each bi- 

 furcation, the lowermost cell is single, or has none opposed to it on 

 the other side of the rachis. This is uniformly the case. Above al- 

 most every pair of polypiferous cells, is to be noticed a pair of smaller 

 cells, not unaptly compared by Ellis to the bowls of tobacco-pipes, 

 with short stems. The larger or polypiferous cells will, in what fol- 

 lows, be termed " cells," and the smaller tobacco-pipe shaped organs 

 will be termed " cups." It may then be stated that usually there is 

 a cup above each cell, and this arrangement obtains throughout the 

 polypidom, excepting immediately below each fork, where the cup is 

 invariably absent above one of the cells of the pair from between 

 which the fork springs. (See fig. passim). 



This is the general arrangement of the cells and cups. It will be 

 less easy to make clear the mode in which the cells and cups are 

 mutually connected, and to render the description of this intelligible, 

 it is necessary to consider each branch as presenting an anterior and 

 a posterior aspect. The former of which is exhibited in fig. 2, a, 

 and the latter in fig. 2, b. 



The celliferous branches originate usually in a short trunk, similar 

 in structure to the radical disk and its branches, and sometimes 



