'joSZrrp?uMS7a'] Bevelopment of Monas Lens. 195 



vaUa7-ia, like the markings of a Pleurosigma, are composed of 

 closely dotted, very minute, bead-like elevations of the surface, and 

 certainly the idea gains some colour from the example before us. In 

 it we find large transparent highly refractive beads, arranged cu'cu- 

 larly in equidistant rows on the body of the animal. May we not 

 therefore infer that, diminished in number, but exaggerated in size, 

 we have the striations of VorticeUa convallaria made apparent ? 

 However this may be, no more striking object for microscopical 

 observation can be found in the whole range of Infusorial life than 

 is presented by a group of these exceedingly beautiful animalcules. 



If these deviations from regular outline in ciliated Infusoria are 

 resultant on hypertrophy, arrest of development principally operates 

 in effecting such changes in the Eotifera — the Tuhicolsn being ap- 

 parently most subject to them. In Melicerta, through successive 

 degradations and the suppression of parts, several varieties are pro- 

 duced, which have been commented upon elsewhere. The Stephano- 

 eeros Eicliornii here figured (5 and 6) presents, however, a generally 

 stunted and abortive growth. Instead of the graceful amphora-like 

 form, surmounted by a crown of elegantly incurved tenacula, bor- 

 dered by verticils of setae, we have a short squab body, planted on 

 an equally short, much corrugated foot, a narrov, though deep 

 infundibulum, supporting five short, obtuse lobes, clothed with rows 

 of long setse, and altogether comparing very unfavourably in appear- 

 ance with the Stephanoceri obtained from the same locality. 



Malformations such as those I have cited have, in my opinion, a 

 value beyond that of mere curiosities, though as such they would be 

 worthy of notice and record ; for may they not help to determine 

 the fixity or otherwise of a species through aberrant forms ? and 

 thus a better knowledge of what is to be regarded as essentially 

 specific be ultimately arrived at. — A imi)er read before the Beading 

 Microscopical Society, February Ibtli. 



YIII. — The Polymorphic Character of the Products of Developnent 

 of Monas Lens. 



By Metcalfe Johnson, M.E.C.S.E. 



In the August number of the ' Monthly Microscopical Journal,' 

 Art. VII., it has been pointed out " that the bearing of the facts there 

 recorded upon Speciology, Epidemiology, and Nature Scavenging 

 will be at once evident." 



Professor Tyndall has recently called public attention to the 

 second point, which has long been the subject of research to scientific 



men. 



o 2 



