^0 Mr. H. J. Carter on the 



evidently the minute spicules with " toothed little disks " and 

 " little points " respectively belonged to Spongilla Jluvi- 

 atilis and S. lacustris. Meyen also stated that the seed-like 

 bodies or spheerulas of Spongilla are " essentially distinct 

 from the sporangia of Algge, and are similar to what are de- 

 nominated the unnter-eggs of polypes " (No. 10, I.e.), which 

 having endeavoured myself to illustrate and confirm in 1859 

 (No. i9), I finally adopted the term " statoblast " (No. 19, 

 p. 340). Lastly, Mr. John Hogg, in 1840, demonstrated 

 beyond question that these " seed-like bodies,^' or statoblasts, 

 germinaU-d in water, and thus reproduced the Spongilla 

 (No. 9). 



In 1842, Johnston published his work on the British 

 Sponges (No. 10), from which the ' Monograph on the 

 British Spongiada3 ' of Dr. Bowerbank is chiefly compiled ; 

 and in Johnston's work an epitome of all that had been made 

 known up to the time was given, not only of Spongilla, but 

 of every other species of the British sponges that had been 

 noticed, together with descriptions and illustrations from 

 actual observation, not only of these but of many others which 

 he added to them ; so that this book is a sine qua non to the 

 student. 



A few years after this, brings us to a period in which, be- 

 sides the reproduction of Spongilla through the " seed-like 

 body," one through sexual elements was also sought for and dis- 

 covered. Thus, in 1856, Lieberkiihn discovered and figured 

 the ovum of Spongilla, together with the spermatozoa (Nos. 14, 

 15, and 16), which, as regards the ovum. Grant had done in 

 the marine sponges in 1826 (Edin. New Phil. Journ. vol. ii. 

 p. 133, pi. ii. figs. 27-29), and, as regards the spermato- 

 zoa, F. E. Schulze confirmed, in 1878, in thfe marine species 

 HoXisarca lohularis (No. 29). I take no account of my own 

 observation of " zoosperms in Spongilla " in 1854 (No. 13), 

 although the absence of the so-called " ear-like appendages " 

 &c. in the figures of them &c. now seems to indicate that 

 they were such, although in the interval I have doubted this, 

 because the fact was not substantiated after the satisfactory 

 manner in which it was subsequently demonstrated by the 

 sagacious Lieberkiihn. 



Thus, then, in addition to the " seed- like body " in Spon- 

 gilla, it was shown that the freshwater sponges could be propa- 

 gated by elements of sexual reproduction like those of the 

 marine sponges. 



Shortly after this, ray own observations (Nos. 17 and 18), 

 coupled with those of James-Clark in 1867 (No. 23), esta- 

 blished the " animality " of Spongilla, together with the form 



