HISTORY OF LITERATURE CONCERNING THE ROTIFERA. 17 



(i) how the Rotiferon, when drawn up into a ball, resists the persistent baking of a summer's 

 sun on the housetop, or the long drought of twenty-one months on the naturalist's desk, 

 without parting with its own internal moisture ; and (ii) why only eighteen or nineteen 

 of his Rotifera (those near the coarse sand) succeeded in rolling themselves up and sur- 

 viving, while the rest perished. 1 



The investigations thus worthily begun by Leuwenhoek were carried on with much 

 spirit by many other observers ; and, during the hundred and thirty-five years that 

 elapsed before 'the publication of Ehrenberg's famous work, " Die Infusionsthierchen," 

 no fewer than sixty of Ehrenberg's species, contained in thirty of his genera, were 

 entered on the list of known Rotifera. 



I have arranged the more striking forms of these in the following table, which 

 classifies them under the heads of some of the families into which I have divided the 

 Rotifera ; 2 and I have added the names and dates of their discoverers ; it will be thus 

 seen how wide a ground had been covered by the early naturalists, since more than 

 half the families have representatives in the table. 



f Stephanoceros Eichhornn . . Eichhorn, 1701 



FLOSCULAKIAD^; ..-,_,.,. . ,, -,r,nn 



1 Floscularia ornata . . . Eichhorn, 1767 



A List of some of the Rotifera discovered before 1838. 



Stephanoceros Eichhornii . . Eichhorn, ] 

 Floscularia ornata . . . Eichhorn, 3 

 I Melicerta ringens .... Leuwenhoek, 1703 



Limnias ceratophylli . . . Leuwenhoek, 1703 

 MELICEBTAD.E . . < T . , . . , . ^ , .,-/ 



Lacinularia sociahs . . . Brady, 1755 



I Megalotrocha alboflavicans . . Eosel, 1755 



, Eotifer macrurus . . . Baker, 1753 



PHILODINAD.E . 1 -i n- T u i ir,n 



( Philodma roseola .... Leuwenhoek, 1702 



HYDATINAD;E . . Hydatina senta .... Miiller, 1773 



SYNCH^TAD^: . . Synchseta Baltica .... Baster, 1759 



NOTOMMATAD;E . . Notommata tigris .... Miiller, 1786 



TKIABTHBAD.K . . Triarthra longiseta . . . Eichhorn, 1775 



/ Brachionus pala .... Joblot, 1718 



BKACHIONID^E . . J Brachionus urceolaris . . . Hill, 1751 



lAnurasa striata .... Miiller, 1776 



PTERODINAD;E . . Pterodina patina .... Eichhorn, 1775 



EtTCHLANiD^E . . Euchlanis dilatata . . . Eichhorn, 1775 



EATTULID/'E . . . Mastigocerca carinata . . . Miiller, 1786 



, Dinocharis pocillum . . . Miiller, 1776 

 DINOCHABID;E . . \ , , . ........ -__,, 



I Stephanops lamellaris . . . Muiler, 178b 



It will be seen that the names of Eichhorn and Miiller occur much more frequently 

 than that of any other observer in this list, and their works on the Rotifera deserve, 

 I think, a special notice. 



JOHANN CONRAD EICHHORN was the pastor of St. Catharine's church at Danzig, 

 and his book on the " Natural History of the Smallest Aquatic Animals " 3 was published 

 in 1781. Though small, it is a most interesting work. He gives figures and descriptions of 

 about a dozen Rotifera that can be identified, including Stephanoceros, Floscularia, 

 Melicerta, Triarthra, Dinocharis, Actinurus, Euchlanis, and Pterodina ; and of most of 

 his species he was the discoverer. 



His enthusiasm is delightful. " I have devoted myself," he says, " to this invisible 

 world, which yields itself to our ken only under the magnifying glass ; and I have, for 

 eleven years, spent my leisure moments on it, so far as my professional duties would 

 permit, in order to know God in His smallest and invisible works ; and I have found 

 Him very great therein. Not the great works only, those vast heavenly bodies 



1 The question will be found fully discussed farther on in the general account of the family 

 Philodinadro. 



2 See chap. III. On the Classification of the Eotifera. 



3 Beitrdge zur Naturgeschichte der kleinsten Wasserthiere. 



C 



