A UTHOR'S INVESTIGA TIONS. I 3 9 



and laid claim in a corresponding manner to the appellation of " micro- 

 spores," In yet other instances the encysted monads were observed to 

 give exit to spores of such excessive minuteness, that, as in the case of 

 several types described by Messrs. Dallinger and Drysdale, they were not 

 individually recognizable as they escaped from the parent cyst, but pre- 

 sented in the aggregate, as viewed with the highest magnifying power, 

 the aspect only of a viscid granular fluid, having a refractive index 

 scarcely higher than that of the surrounding water. The recurrence of the 

 various monad forms just enumerated by no means, however, exhausts 

 the evidence of latent or pre-existing life found accompanying well-nigh 

 every fragment of hay examined. The spores of fungi occurred in abun- 

 dance, and also ciliate Infusoria, such as Voi'ticella, Colpoda, and TricJioda, 

 in their resting or encysted state, while Bacteria were never absent. These 

 latter, as time progressed, developed their several motile, glcea, and fila- 

 mentous phases, and were repeatedly, with the assistance of the ^-^-\\\z\\ 

 objective, demonstrated to increase by means of minute internally pro- 

 duced spores, after the manner of the co-associated monads. Some idea 

 of the conditions under which the spores and encystments of the various 

 animalcules present themselves in connection with hay-fibres, as viewed 

 with a high magnifying power, may be arrived at on reference to the upper 

 portion of PI. XL, which, with its accompanying explanation, is devoted to 

 the special illustration of this topic. 



From the foregoing detailed account of the life-history of one special 

 monad type, and of the circumstances under which the spores of this and 

 other species are found primitively attached to the macerated hay, there 

 would appear to be little left to prove the utter untenability of the argu- 

 ments adduced by the heterogenists in favour of the de novo generative 

 properties of this material. One important link in the chain, neverthe- 

 less, remains to be filled up. So far it has not been shown under what 

 circumstances these countless multitudes of spores became originally 

 deposited upon, and attached to, the dried hay fibre, and such an absence 

 of definite demonstration might be interpreted by the heterogenists in 

 favour of their having been developed there spontaneously. Of the larger 

 Ciliate species it has been frequently suggested that they are derived from 

 animalcules carried by river inundations on to the low-lying meadow lands, 

 and which have remained attached in their encysted state to the grass on 

 the retreat of the overflowing waters. Such an interpretation, however, 

 necessarily implies a local and restricted distribution only, and in no way 

 accounts for the unexceptional and cosmopolitan distribution of Infusoria 

 and their germs upon hay derived from whatever source. Neither, again, 

 does the vast quantity, and definite disposition of the spores with rela- 

 tion to their vegetable matrix, allow of the alternative that they have 

 simply fallen from the surrounding atmosphere, and which, in point of 

 fact, can be no more regarded as their native or parental element than it 

 is that of the floating thistle-down. 



