ORIGIN OF THE ANIMATED TEIBES. 119 



mosses, M. de Brebisson states, that, a pond in the neighbour- 

 hood of Falain having been rendered dry during many weeks 

 in the height of summer, the ground was immediately and 

 entirely covered to the extent of many square yards by a minute 

 compact green turf, formed of an imperceptible moss, the 

 Phaseum axillare, the stalks of which were so close to each 

 other, that upon a square inch of this new soil might be 

 counted more than five thousand individuals of this minute 

 plant, which had never previously been observed in the 

 country. Some cryptogamic plants again are found only on 

 particular artificial substances. The white mould on ink, for 

 instance, is invariably the same, and yet different from any 

 other fungus. Some are found only on certain animal sub- 

 stances, as parings of hoofs, horn, bone, &c. Some are peculiar 

 to hospitals, where they grow parasitically from the wounds of 

 the patients ; whole crops of them being sometimes found on 

 the removal of the dressings. Sowerby, in his Fungi, gives us 

 one peculiar to the modelling clay of sculptors. 1 The ordi- 

 nary way of accounting for these phenomena is to assume that 

 the seeds of the plants either resided in a state of dormancy in 

 the earth, or were brought to the spot by winds ; but there is 

 scarcely a single instance of living seeds being detected in 

 earth brought up from mines or wells, and some of the seeds 

 assumed to be transported through the air are too heavy for 

 that purpose, not to speak of the unlikelihood that such seeds, 

 granting they were transportable, should take root exclusively 

 on a new surface, many miles from their native ground. 



It has been shown by the opponents of this doctrine, that 

 when a vegetable infusion is debarred from the contact of the 

 atmosphere, by being closely sealed up or covered with a 

 layer of oil, or only receives oxygen which has passed through 

 sulphuric acid, whereby all animal admixtures have been de- 

 stroyed, no animalcules are produced ; but can we be sure, in 

 such circumstances, that we have not set aside some other 

 simple condition requisite for a non-ex-ovo generation ? Who 

 can tell what effect such exclusion of air, or such mode of ad- 

 mitting oxygen, may have upon the operation of the impon- 

 derables in the case? To this I do not believe that any 

 satisfactory answer could be given. 



Seeing such reasons for believing the general dictum of the 

 philosophical world on primitive generation to be at least in- 



1 The range of facts here adduced is partly from the manuscript of an 

 obliging correspondent, and partly from a brief article on Spontaneous 

 Generation of Plants, in Jameson's PhilosophicalJournal, January, 1836. 



