ORIGIN OF THE ANIMATED TRIBES. 93 



an authentic case under my notice) the spot is man) mile9 

 from where clover is cultivated, and that there is nothing 

 for six feet below but pure peat moss, clover seeds being, 

 moreover, known to be" too heavy to be transported, as 

 many other seeds are, by the winds. Mushrooms, we 

 know, can be propagated by their seed ; but another mode 

 of raising them, well known to the gardener, is to mix 

 cow and horse dung together, and thus form a bed in 

 which they are expected to grow without any seed being 

 planted. It is assumed that the seeds are carried by the 

 atmosphere, unperceived by us, and, finding here an ap- 

 propriate field for germination, germinate accordingly; 

 but this is only assumption, and though designed to be on 

 the side of a severe philosophy, in reality makes a pretty 

 large demand on credulity. There are several persons 

 ejpnent in science who profess at least to find great diffi- 

 culties in accepting the doctrine of invariable generation. 

 One of these, in the work noted below,* has stated seve- 

 ral considerations arising from analogical reasoning, which 

 appear to him to throw the balance of evidence in favor 

 of the aboriginal production of infusoria, f the vegetation 

 called mould, and the like. One seems to be of great 

 force ; namely, that the animalcules, which are supposed 

 (altogether hypothetically) to be produced by ova, are af- 

 terwards found increasing their numbers, not by that 

 mode at all, but by division of their bodies. If it be the 

 nature of these creatures to propagate in this splitting or 

 fissiparous manner, how could they be communicated to 

 a vegetable infusion ? Another fact of very high import- 

 ance is presented in the following terms : " The nature of 

 the animalcule, or vegetable production, bears a constant 

 relation to the state of the infusion, so that, in similar cir- 

 cumstances, the same are always produced without this 

 being influenced by the atmosphere. There seems to be 

 a certain progressive advance in the productive powers of 

 the infusion, for at the first the animalcules are only of 

 the smaller kinds, or monades, and afterwards they be- 

 come gradually larger and more complicated in their 

 structure ; after a time, the production ceases, although 

 the materials are by no means exhausted. When the 



* Dr. Allen Thomson, in the article Generation, in Todd's Cy 

 clopaedia of Anatomy and Physiology. 



f The term aboriginal is here suggested, as more correct than 

 spontaneous; the one hitherto generally used. 



