A Contiibut. to the Embryol., Life-histoi-y, and Classificat. of the Dicyemids. 89 



In the centrai celi (germogen) of the Infusorigen are seen a few loose 

 germ-cells and a large nucleiis {n"). The Infusorigen represents a 

 Gastrula like that of the vermiform embryo. Acetic acid. 



Fig. 111. One of two Infusorigens from a Rhorabogen 2 mm long. In front are 

 seen two germ-cells in process of cleavage ; behind, one germ-cell 

 {ig), one 8-cell stage, one outlined embryo, and the paranucleus [n']. 

 Acetic acid. 



Fig. 112, 113. Two portions ot the same axial cell [Dicyemennca Eledoncs, 

 2.4 mm), showing the final products of two Infusorigens. The germ- 

 ogen (e) consists of a granular body and a large nucleus («") , and 

 lies in the midst of small loose germ-cells, which are destined, after 

 a period of multiplication by division, to become vermific germ-cells. 

 Acetic acid. 



From a transitional 2. -5 mm long, showing same Clements. 

 A similar portion from another individuai 2.4 mm long. Acetic acid. 

 Portion of the axial cell of an individuai .7 mm long. An unusual forra 

 of the Infusorigen. 



A transitional condition similar to figs. 112 — 115. From an individuai 

 1,45 mm long. Osmic. acid. 

 A free germogen with several nuclei. 



