8G MR. H. CHARLTON BASTIAN'S MONOGRAPH 



tomical peculiai-ities which distinguish them from their less fortunate allies. It is an 

 establislied fact that the young- of the so-called Vibrio tntici are capable of resuming 

 their activity, by immersion in water, after having remained dormant within their seed- 

 like gall for a period of twenty-seven years, since Baker was enabled to establish this 

 fact in 1771 with specimens given to him by Keedham in l?-!! ' ; and I have lately 

 been informed by one of the Eellows of this Society* that he has succeeded in restoring 

 them after a period of " about twenty years," though it Avas stated by Bauer in his well- 

 known paper in the ' Philosophical Transactions' for 1822 ^ and by other ol)servers, that 

 from five to eight years Avas the limit; whilst lately, in his valuable work on 'Entozoa,' 

 Dr. Cobbold has reported the period to be no more than " four or even five years." These 

 discrepancies depend doubtless to a certain extent upon the manner in which the gall 

 has been preserved during the interval, and upon certain differences in the hygrometrical 

 conditions to which it has been subjected, just in the same way as seeds retain their 

 power of germination for a variable period imder the influence of different methods of 

 preservation. I have been able to verify the observations of Spallanzani, Dujardin, 

 and others, regarding the degree of vitality of the Nematodes found in tufts of moss, 

 though they do not in reality belong to the genus Ehabditis, 'as reported by Dujardin, 

 but are distinct forms, which I have included in the genera Fleet us and Aphelendms. 

 And, more marvellous still, I took, this summer, during the long-continued drought of 

 months, from the top of a slate roof with a southern aspect, and fully exposed to the 

 direct rays of the sun, a patch of the yellow lichen, Parmelia parietina, for the purpose 

 of examination — though more Avith a view of making quite sure that there were no Nema- 

 toids in it than Avith the expectation of finding any — Avhen, after placing a small portion 

 Avith some water in a Avatch-glass, I Avas extremely surprised on looking at it with a 

 lens about two hours afterwards, to see forty or fifty of these little Nematodes in the full 

 SAving of life and activity. But Avith these other Nematoids of moss and lichen it is not 

 as with the Vibrio tritici, that this remarkable poAver is possessed only by young and 

 immature individuals, since it is enjoyed also by adults having fully developed ova AAithin 

 them. I have found no representatives of these particular types in salt Avater ; and, as 

 far as my experience goes, those found in this situation are all incapable of being revived 

 after having remained without Avater, on a slip of glass, for a few minutes. A statement 

 apparently in direct opposition to this was made by Otto Mlillcr in his ' Animalia Infu- 

 soria.' Tavo marine species, named by him Vibrio gorcUiis and V. anguillnla marina 

 respectively, were stated to revive after desiccation by the addition of spring Avater ; but, 

 since he does not make any definite statements concerning the length of time during 

 Avhich the moA'ements continued, I suspect that what he observed may be nothing more 

 than Avhat I have myself seen very frequently, namely, two or three tolerably brisk con- 

 tractions immediately on the addition of the water, gradually becoming less marked, and 

 finally ceasing altogether in less than a minute. This effect I imagine to be physical 



' Lc'ttre de Xeedhr.ni en rqonse an mtmoire de EofFiedi, dans le Journ. de Phys. de I'AbbJ Rosier, t. v. p. 227, 



1/75. 

 = \V. 11. Ince, Esq. 



^ "Microscopical Observations on the Suspension of the Muscular Motion of the Tihrio iritici." 



