136 I. iJBrA : hexactinellida. i. 



which is directly continuous with tlie thin lateral processes. I 

 have noticed no appreciable difference in the convexity of the 

 two sides of the nucleus, nor have I detected the presence at its 

 distal surface of a strongly colored cap-like body, such as was 

 seen by F. E. Schulze in Schaudinnia arctica. 



The protoplasm of the nodes and beams, as it appears in 

 hardened preparations colored with carmine or hœmatoxylin, both 

 of which usually stain it but very faintly, consists of a clear 

 matrix containing granules that are neither uniform in size nor 

 in distribution. The limit of the matrix against the meshes is 

 often scarcely perceptible, on account of its perfect clearness ; 

 in fact, the protoplasm presents itself to the eye almost by its 

 granules alone. These are, as have also been noted by F. E. 

 Schulze, frequently arranged in strings, an arrangement which 

 seems to me to be simply due to their situation one behind 

 another ia narrow tracts of the matrix. In some preparations 

 and sometimes in certain parts of a single preparation, I have 

 found in greater or less abundance unusually coarse and réfrin- 

 gent granules (fig. 38), wdiich elsewhere are either quite absent 

 or only solitarily present. They remain unstained by borax- 

 carmine but readily take up acid-fuchsin. Their presence or 

 absence presumably depends upon certain metabolic conditions 

 of the choanocytes ; they are possibly somewhat allied to, if not 

 identical with, the inclosures of the thesocytes to be described 

 further on. 



Stained with acid-fuchsin, the protoplasm becomes tolerably 

 well colored. It then appears at places nearly homogeneous or 

 uniformly finely granular, and in other places with the coarser 

 well-stained granules in addition (figs. 37, 38). As before men- 

 tioned, its external limit against the meshes stands out well 



