198 • ERNEST WAEERN. 



tures in tlie gonopliores. Tlie organisms have not been 

 found outside the hydroid, either adhering to the surface of 

 the perisarc^ or to the sea weed or other foreign body to which 

 it is attached. The structures occur especially in the four 

 canals of the umbrella cavity left between the ectotheca and 

 endotheca, and alternating in position with the radial endo- 

 dermal canals (text-fig. 4, A and b). They may also be found 

 in cavities that occur in the spermatic mass (PI. XXXIV, 

 fig. 6, ch.), and between the ova or developing planulte of a 

 female gonophore. 



The youngest stage observed is seen in PI. XXXIV, fig. 7 

 (i). It is a rounded body, about 2"2 /i in diameter, and 

 staining wath hgematoxylin or aniline dyes with great diffi- 

 culty. The body is refringent, and appears homogeneous 

 with Zeiss's DD objective, but with Zeiss's apochromatic ^w 

 it is seen to be slightly granular with one or two minute 

 globules. In this stage it is capable of division. I have 

 found such bodies embedded in the spermatic tissue, and in 

 one case in the ectoderm of the ectotheca. The bodies 

 apparently Avork their way out into any spaces, such as the 

 umbrella-cavity and channels, and any cavities in the sper- 

 matic mass (PI. XXXIV, fig. 6, h) or between the ova. No 

 distinct, separable cell-wall can be observed. 



When in a cavity the body soon secretes a ti^ansparent and 

 refringent envelope of one or two layers (fig. 7 {3, S, 4, 

 and S)). This envelope, especially the outermost and older 

 layer, is capable of staining deeply with hasmatoxylin (PI. 

 XXXIV, fig. 8 U), o.en.). 



In this condition (fig. 7 {4) ) it is capable of fission, both 

 the central body (c. b.) and the envelope dividing. 



The envelope, forming a definite capsule, increases in size 

 and in the number of laminations, and the central body 

 becomes smaller and more refringent. The central body, which 

 in the young stage is rounded and about 2'2/i in diameter, 

 varies in size in the fully-grown capsule from about PIO^ 

 to 0*48^ (figs. 9 and 10, ch. and d.l.). The central body can 

 divide by fission [d.Jj.) inside the capsule. Previous to fission 



