E. MAKSHALLI. — FLAGELLATED CHAMBER. 141 



positions, wliile the trabeculse suspending the chamber-wall suffer 

 at places unnatural slackening and at other places tightening, or 

 are even wholly broken off. The consequence is that the chambers 

 mostly lose their original inflated form and may even become 

 shriveled up, which is probably to be explained by the inherent 

 contractility of the choanocytal protoplasm. The chamber-wall 

 then does not show the reticular structure ; I suppose the meshes 

 have been obliterated as a result of the contraction. At the best 

 it presents itself as a continuous layer of densely but irregularly 

 granular protoplasm. In optical section it appears somewhat 

 thicker than when seen in hardened preparations. Under favor- 

 able circumstances, the flagellation can be distinctly observed, 

 though no longer in motion. The flagella seem to be somewhat 

 more densely situated than in hardened preparations, which 

 apparently stands in relation with the contracted state of the 

 chamber-wall. I have also seen a number of flagella apparently 

 emanating from little masses of granules in teased preparations. 

 The collar in the fresh state I have not succeeded in detect- 

 ing. This failure was undoubtedly due to the fact that at the 

 time of my investigations on fresh specimens, years ago at the 

 Misaki Marine Laboratory, I had no knowledge of the Hexacti- 

 nellidan collar and moreover no higher power at my disposal than 

 Zeiss' objective DD, which, as I afterwards learned, is by far 

 too weak for the clear observation of the structure in question. 

 It may here be mentioned that in a sketch which I made, in 

 1895, of the chamber-wall of Acanthascus cactus as examined in 

 optical section in the fresh state, I find the flagellation represent- 

 ed by a series of lines of unequal lengths, the shorter of which 

 are confined to the base in junction wâth the layer of granular 

 protoplasm. It occurs to me as quite possible that I have seen, 



