300 Dli. G. P BIDDER ON THE 



belonged to the sponge; the tail was stiff*. Figs. 4, 5, and 6 represent 

 the emergence from [or entrance into] gonocytes in the cloacal wall of 

 S. raphanus aquariensis of curious spherical cells with protruding button-like 

 nuclei, which I call "dolly-cells," from the shape of a washerwoman's 

 " dolly" of blue. These can be seen in some preparations in great numbers, 

 and I suppose them (1892 b, p. 479, footnote) to be spermatozoa in the 

 antecedent [or subsequent] stage to figs. 1 and 2. It is difficult to think of 

 any alternative explanation ; the contents of the gonocyte-iike cells from 

 which they emerge are spherules each with a staining-spot (fig. 4), 

 undoubtedly not falciform, so that if the "dolly-cells" are parasitic they 

 are certainly not Gregarines [see Postscript, p. 302]. 



The organisms in the chambers of Grantia compressa which I described as 

 Algae (1895, p. 31), Dendy (1914) has rediscovered as sperm-morulse ; and 

 the objects which I identified as fasces from the collar-cells (1895, p. 18, 

 fig. 13) he conjectures to be clumps of spermatozoon-heads (1914, fig. 93); 

 but these new interpretations seem improbable t, and we are left to rely on 

 Polejaeff's observations (cf . infra, " Syncrypta spongiarum," p. 305, and 

 Note D, p. 319). 



For the Calcinea, Vosmaer (1887, p. 412) observed a sperm-ball in an 

 Ascon, and I have sketched similar structures (see next paper) in Clathrina 

 clathrus ; but the objects drawn by me might have been an alga, like that 

 observed by me and by Dendy in Grantia comp>ressa. Thej r are clos'ely the 

 same size as the " morulas " drawn by Dendy, and the following observation 

 is against their being spermatoblastic. 



In the Calcinean Guancha coriacea tropus primordialis, I was fortunate 

 enouo'h to observe, pouring out in a cloud from one part only of the sponge- 

 wall, a number of. similar objects (PI. 24. fig. 7) which are difficult to interpret 

 except as spermatozoa. Unfortunately the preparation was in iodine and 

 sea-water, so that it is impossible to say what was the mobility of the 

 organisms, but their appearance suggests that they are more wriggling than 

 swimming organisms!. Reference to Minehin's figures and description 

 (1897, p. 499, figs. 17, 19, and especially 41) shows identity of shape and 



* These two figures are drawn from the same object. Fig. 3 is sketched from a smaller 

 stiff-tailed organism found free in the flagellate chamber on another occasion. 



t Dendy's drawings, as always, convince anyone who knows the material of their absolute 

 fidelity. I feel no doubt from his figs. 83 and 84 that his collar-cells actually fed on the 

 alga which I was unable to follow further than the finding single monads inside the 

 collars. He will be interested to note in my paper of 1895 that I recorded the fonr-celled 

 stage of the alga which he (p. 364) found unaccountably absent : it was without covering- 

 cell, as are his figs. 86, 88, 89, 90, 91 ; the four deeply-stained spherules lay imbedded in a 

 sphere of transparent substance, rather more plentiful, proportionately, to the spherules than 

 in Dendy's fig. 89. Fig. 84 closely resembles a sketch I have of a collar-cell which has 

 ingested a large starch-grain. 



1 [It is of course possible that they develop a flagellum after extrusion. 1 



