SPONGE WEAVERS. 133 



method is still but imperfectly known. In the 

 ordinary sponges of commerce, as dredged, and 

 before they are cleaned and manipulated by the 

 dealers, the microscope reveals myriads of minute 

 ovoid bodies surrounding the fibres, immersed in the 

 sarcode, which are believed to be the eggs, or ova, 

 of this particular class of sponges, and are as yet 

 the only kind of reproductive bodies found in them. 

 In size and appearance these ova have a great 

 resemblance to the ova produced in the more legi- 

 timate manner, and are about two micro-millimetres 

 in diameter, so that it would take something like 

 twelve thousand, placed side by side, to form a line 

 an inch in length. This is almost all that is at 

 present known about them, but they, or their ana- 

 logues, do not appear to be confined to the keratose 

 or horny sponges. 1 



1 Saville Kent investigated this subject, in connexion with 

 his " History of the Infusoria," and found them by thousands 

 in several species of sponge. His conclusion is "that the 

 collared sponge monad (already described), after assuming a 

 quiescent state, divides by segmentation into a mass of charac- 

 teristic microspores, and, these falling asunder, become dis- 

 tributed throughout the hyaline stratum." And again, " these 

 spores distributed broadcast through the substance of the 

 sarcode stratum (cytoblastema) may be met with and traced 

 onwards through every intermediate size and stage, from the 

 single sphaeroidai spore, up to the adult collared monads, or 

 amcebiform bodies ; the derivation of these spores through the 

 splitting up into a granular or sporular mass of the entire 



