DESCRIPTION OF EPHTDATIA BLEMBINGTA. 83 



wish it to be inferred that I am of opinion that the seed-like 

 body is but an aggregate of separate sponge-cells ; " and 

 further^ after describing certain cells of the sponge^ he says : 

 " It may, perhaps, be one of these cell-bearing cells which 

 becomes the seed-like body." 



Lieberkiihn (12), in the year 1856, published an account 

 of the origin and structure of the gemmule. He found in 

 the deeper parts of the sponge shiny white gemmules, Avhich 

 on the whole appeared like ordinary brown gemmules, and 

 which possessed exceedingly plain amphidiscs. He also found 

 other gemmules, distinguished by their very delicate trans- 

 parent shells, also possessing very obvious amphidiscs. These, 

 he said, had a superficial layer of a substance feebly refrac- 

 tile, and a central mass brilliantly refractile. The feebly refrac- 

 tile cells separated easily, while the others only did so with 

 difficulty. In these bodies he was not able to find the delicate 

 transparent encrusting layer, which he had seen round the 

 white gemmule ; but found a layer of cell-like spherules which 

 resembled the ordinary sponge-cells in the arrangement of 

 their granules and of their nucleolus ; while others contained 

 the amphidiscs. Some of the enclosed amphidiscs had exactly 

 the shape of those found surrounding the ordinary gemmule. 

 Others, he said, did not possess the two discs, but in the 

 interior of each cell-like structure there Avas a delicate rod 

 with a slight knob-like swelling at each end. In others a 

 series of very fine spicules radiate from the terminal SAvelling. 

 He derived the amphidiscs by imagining these spicules to 

 become broader, and the axial rod to become thicker. The 

 contours of the cells containing the spicules were described 

 as being as sharp as those of ordinary sponge-cells. He could 

 find no nuclei in these cells. He finally concluded that these 

 bodies were incompletely developed gemnuiles. He also 

 found certain bodies which he described as white aggregations 

 of sponge-cells, possessed of the same size and shape as 

 ordinary gemmviles. In the same year he published a second 

 paper, in which he summed up as follows (13) : — " That the 

 gemmules are derived from a heap of ordinary sponge-cells 



