32 DEVELOPMENT OF 



For observations and researches on the genus Cam^a- 

 nularia which have enabled us to institute this compa- 

 rison, science is obhged especially to Rapp, Grant, Lister, 

 and Loven. 



I will here, as briefly as possible, give the results of 

 the observations of the last-named Swedish naturalist, 

 but for the observations themselves, must refer to the 

 sources whence my abstract is drawn, namely the ' Kgl. 

 SvenskaWetenskapsAkademiensHandlingar,' (1835,) and 

 ' Wiegman's Archiv, f. Naturg.,' (1837, s. 249—262, tab. 

 vi,) whence I have taken the figures (48 — 58) given in 

 tab. I. of this work, which afford us a striking example of 

 cyclical development, and throw a clear light on all the 

 neighbouring families both above and below. 



Eig. 48 represents a Campanularia geniculata or bell- 

 shaped Polype very slightly magnified. It is evident, 

 that the individuals, which, surrounded by cells or cups, 

 shaped like inverted cones or bells, constitute one of these 

 poljrpes, have cells of three kinds, each of which has a 

 determinate position. The most numerous are the smaller 

 cells (individuals) placed at the extremities of the stem 

 and branches (fig. 48 aa^ In the angles between the 

 branches and the stem are situated the axillary cells, 

 which are always longer and nearly twice as large, (fig, 

 48 h h^ and upon these are placed the third kind of 

 cells which are globular (fig. 48 c c,) and the smallest 

 of all. The relation between the three groups of indi- 

 viduals or cells differing thus in form and position, be- 

 comes clear, only when the development of the whole 

 polype is traced, and a moderately high power employed 

 for the purpose. The minute vesicular individuals (fig. 

 48 c c and fig. 53 a and (5) which are placed upon the 

 larger and longer axillary cells, contain two, and rarely 

 three moderately large ova, which exhibit the essential 

 parts of an ovum, and the individuals in which they are 

 contained, are thus to be considered as, in reality, 

 females, 

 , When the thin membrane of the ovum bursts asunder. 



