560 EHRENBERO ON THE ORIGIN OF ORGANIC MATTER 



pound microscope from Nurenberg, which I had, according to mj' own 

 views and wants, rendered more powerful, the same indeed with which 

 I had ah'eady discovered the germination of the seeds of moulds, which 

 however was far inferior to the ingenious microscopes of that time. 

 Those observations appeared, however, to my friend to be so unques- 

 tionable, that he would not forego the opportunity of making known the 

 principal points in his book. 



From 1820 I made my observations in Africa with a microscope 

 made by Hofmann of Leipzig, of the cost of about £6, which, with a 

 greater magnifying power, gave a much better image ; and from the 

 year 1824 I used together with that an English microscope by Bleuler, 

 which cost about £15, and the power of which was still higher. With 

 these instruments I followed up the critical investigation of the generatio 

 primitiva with increasing care ; and the more exact my observations 

 were, the colder I became towards the idea of an instantaneous coagu- 

 latiori of primitive substances into an organized being. In the whole 

 series of years, during which I have sometimes for days together conti- 

 nued those observations, I never, not eveji in a single instance, saw the 

 subitaneous origination from slime, cellular tissue of plants, &c., of those 

 minute organic bodies to me so well known ; still much less had I ob- 

 served the gradual development of elementary outlines that had suddenly 

 originated, of Entomostrati and other larger animalcules ; which was an 

 extraordinary delusion of M. Fray, who took the exuvice and fragments 

 of minute dead animals for sketches and rudiments of new generations *. 



My observations pursued in Africa convinced me more and more 

 that the origin of the most minute organized beings must also be cycli- 

 cal ; for although circumstances did not enable me there to bring to a 

 completion my investigations into the structure of the Infusoria, yet I 

 found always a manifest repetition of forms similar to those which I had 

 determined by drawings and measurements, and not at all that unlimited 

 variation of them which we should expect from the idea of a metamor- 

 phosis of destroyed organic substances into undetermined elementary 

 forms of life. Thus the basis on which my observations proceeded 

 continually became firmer. Corti's discovery, that the eggs of some 

 Infusoria (^Brachionus) burst when the young ones creep out, and leave 



* Essai sur I'Origitie des Corps organises et hiorganiscs, par Fray. Paris, 

 1817 ; p. 71. " J'ai vu des monocles, des polypes, des vers et d'aiitres unimaux, 

 qui netaient encore qu'ebauc/ies ; la forme exterieure etait jelce, mais finte- 

 rieur n'amiit pas re^u tons les globules aclifs qui deoaient le constituer. Ces 

 esquisses etaient encore immohiles." This puts one in mind of the celebrated 

 ancient Egj'ptian frogs, which were said to come into existence after the inun- 

 dation, and to hop about with only their fore part developed, while their hinder 

 part was still mud. Times are altered; for he that sees such frogs at the present 

 time, does not, even in Egypt, stand with trembling awe at a distance from them, 

 biU lays hold of th<?m, and finds that under llie mud of the hinder part some- 

 thing more than outlines are hidden. So it was with me at the Nile ; for I came 

 there indeed as a sceptic. 



