V.] SPECIFIC STABILITY. 129 



of the original 'ones." These, however, may be said to be 

 the same species, after all ; but recent researches by Dr. H. 

 Charlton Bastian seem to show that modifications in the 

 conditions may result in the evolution of forms so diverse 

 as to constitute different organic species. 



Mr. Murphy observes 8 that " it is scarcely possible to 

 doubt that the various forms of fungi which are character- 

 istic of particular situations are not really distinct species, 

 but that the same germ will develop into different forms, 

 according to the soil on which it falls ; " but it is possible 

 to interpret the facts differently, and it may be that these 

 are the manifestations of really different and distinct spe- 

 cies, developed according to the different and distinct cir- 

 cumstances in which each is placed. Mr. Murphy quotes 

 Dr. Carpenter * to the effect that " no Puccinia but the 

 Puccinia rosce is found upon rose-bushes, and this is seen 

 nowhere else ; Omygena exigua is said to be never seen 

 but on the hoof of a dead horse ; and Isaria felina has 

 only been observed upon the dung of cats, deposited in 

 humid and obscure situations." He adds, " We can scarce- 

 ly believe that the air is full of the germs of distinct spe- 

 cies of fungi, of which one never vegetates until it falls on 

 the hoof of a dead horse, and another, till it falls on cat's 

 dung in a damp and dark place." This is true, but it does 

 not quite follow that they are necessarily the same species, 

 if, as Dr. Bastian seems to show, thoroughly different and 

 distinct organic forms B can be evolved one from another 

 by modifying the conditions. This observer has brought 

 forward arguments and facts from which it would appear 

 that such definite, sudden, and considerable transforma- 

 tions may take place in the lowest organisms. If such is 

 really the case, we might expect, a priori, to find in the 



3 " Habit and Intelligence," vol. i., p. 202. 



4 " Comparative Physiology," p. 214, note. 



6 See Nature, June and July, 1870, Nos. 35, 36, 37, pp. 170, 193, 219. 



