MODERN BIOLOGY 417 



of making a journey through Europe, thereby increasing his knowledge and 

 widening his connexions. Having returned home, he received an oflicial ap- 

 pointment, but resigned from the Government service upon contracting a 

 wealthy marriage, and afterwards lived as a private scholar until his death, 

 in 1784. His most important work was published posthumously. During his 

 lifetime he was generally regarded as an amiable and kind-hearted man, 

 though somewhat vain. Of his immense literary production one or two zo- 

 ological works have preserved his name for posterity. 



As will be realized from the above, O. F. Miiller as a zoologist was es- 

 sentially autodidactic; he had educated himself by studying the writings of 

 Linn^us, but he devoted his research work to spheres that Linnaeus and his 

 pupils had overlooked. In two works, Entomostraca Dania and Hydrachna, 

 he describes in detail, and extremely well considering the period, two hith- 

 erto entirely neglected groups of Articulata. Still more remarkable are his 

 two works on the Infusoria, the last of which, mentioned above, was pub- 

 lished by Fabricius in 1786. In these works he makes an attempt for the first 

 time to present a systematic description and classification of the Infusoria, 

 supplemented with detailed diagnoses of genus and species and illustrated 

 with accurate and finely drawn pictures. Quite a number of them, especially 

 the larger Ciliata, he has described so well that they are still recognizable 

 and their names are still in use today. As was usual in his age, he paid but 

 little attention to the internal structure of the creatures; in regard to the 

 origin of the Infusoria, he believes in the spontaneous generation of the lesser 

 forms, while assuming that the larger and more highly developed forms mul- 

 tiply by reproduction. 



O. F. Miiller's contemporaries and immediate successors made a number 

 of fresh discoveries in the sphere of the Infusoria, as well as various attempts 

 to systematize the forms already known. The same period that gave rise to 

 cell research — the eighteen-thirties — provided also a fresh impetus to mi- 

 crobiology. In this the pioneer was Christian Gottfried Ehrenberg. Born 

 in 1795 in the neighbourhood of Leipzig, he studied medicine there and was 

 afterwards given an opportunity of making a six years' voyage of explora- 

 tion to the East, whence he brought home important collections. This ex- 

 pedition having brought him fame, he was invited to accompany Humboldt 

 on his Asiatic expedition, after which he became professor of medical his- 

 tory at Berlin and secretary to the Academy of Science there. He died in 1876, 

 having long given up active participation in scientific developments. 



Infusoria as " complefe organistns" 

 Ehrenberg's great contribution to biology was his work on the Infusoria, 

 the results of which were published originally in a number of brief essays 

 and afterwards in the important and splendidly got up work entitled Die 

 Infusionstiercben als vollkomtnene Organismen, printed in 1838. The result of this 



