Transmutation of Form in certain Protozoa. 223 



from a common trunk, and drawing their origin from a common 

 root, branches bearing all manner of flowers, every fashion of leaves, 

 and all kinds of fruit, and these for every use. 



"Professor Haeckel looks upon the causes which have led to 

 the present diversity of living nature as twofold. Living matter, 

 he tells us, is urged by two impulses — a centripetal, which tends to 

 preserve and transmit the specific form, and which he identifies with 

 HEREDITY, and a centrifugal, which results from the tendency of 

 external conditions to modify the organism and afiect its adaptation 

 to themselves." * According to M. Famitzen, the gonidia of 

 lichens, if maintained in a condition of humidity on the surface of 

 bits of bark for several months, will give rise in their interior to 

 zoospores, that is, to uniform corpuscles provided with definite move- 

 ments by vibratile cilia hke the zoospores of Algse.f 



Mr. Browning t says, " Many of those who are still sceptical as 

 to heterogeny admit that they have watched the conversion of bac- 

 teria into fungoid growths, and some have even alleged that they 

 have witnessed the conversion of bacteria into infusoria." 



We find in the natural history of Protococcus pluvialis,^ " The 

 motions of the various forms of Hasmatococcus are there described, 

 and appear to be very like those of Euglena viridis; in fact, so 

 much so that Flotow himself compares them with those of Astasia 

 joluvialis." 



Griffith and Henfrey say,|| "The forms included under the 

 family thus characterized are still very imperfectly understood, and 

 it is probable that some of them, separated generically by Ehren- 

 berg, are only transitional conditions of others." 



Harvey says,1[ " We might readily take for a Protococcus or 

 other simple Alga what are only the spores of a conferva. 



" The granules of which the green matter is composed detach 

 themselves from the mass one after another, and having thus become 

 free they move about in the vacant space of the joint with an 

 extreme rapidity." 



Professor Wilhamson, speaking on Spliserosira volvox** says, 

 " In this stage of its development each protoplasm bears the closest 

 possible resemblance to an Euglena. The motile condition of the 

 Protococcus pluvialis, I am convinced that if one of the gemma of 

 Sphserosira and an individual Euglena viridis were placed side by 

 side they would be wholly indistinguishable." 



In order to commence this investigation I will append a few 

 observations I have made on various forms of Paramoecium, and I 

 shall endeavour to show that it constantly transforms to Vorticella, 



* Huxley, 'Academy,' Oct 9, 1869. 



t ' Quart. Journal of Science,' Oct., 1869. % ' M. M. J.,' July, 1869. 



§ Kay Soc, 1853, p. 522. || ' Micrographic Dictionary,' p. 75. 



^ ' Harvey's Manual,' p. 29. *♦ ' Pop. Sci. Eeview,' July, 1870. 



