ON VARIETIES, RACES, SUB-SPECIES, AND SPECIES. 81 



one and the same genus, which have been submitted, in their 

 development, to tiie influences of identical circumstances. 



(A.) Amongst the animals preserved by the ancient Egyptians, 

 some have been found in such a perfect state, that their identity 

 with animals now existing has been conclusively ascertained. 

 Take for example the complete identity found to exist by Cuvier 

 between the Ibis of ancient and modern times. So in plants ; 

 M. Loiseleur-Deslongchamps has demons) rated that the wheat 

 of our own day is identical with that found in the ancient Egyp- 

 tian catacombs, at least 3000, and perhaps 4000 years old. The 

 last named gentleman has shown that wheat does not proceed 

 from any species of jEgilops, as has been stated even in modern 

 times, and that it is difficult to place it, as it was by Buffon, 

 among those plants wliich have been so modified by cultivation, 

 tliat even if their original type has not disappeared entirely from 

 the face of the earth, at least it has not been recognised among 

 living plants. 



(B.) We have not been able to ascertain that any permanent 

 modifications in the annuals constantly raised from seed in bo- 

 tanic gardens have ever been observed. We may mention, that 

 for 30 successive years at least, 150 varieties of grasses were 

 sown by M. d'Albret, of the Royal Gardens, and these varieties 

 constantly appeared with their peculiar essential characters ; so 

 with the numerous seedlings raised by M. Pepin, of the Botanic 

 Garden in the same place, they always represented their re- 

 spective parents, and among these plants were JEgilops ovata, 

 squarrosa, and Iriuncialis, which had been constantly raised 

 from seed for upwards of twenty years. 



As another example of the uncliangeableness of specific cha- 

 racters in the same circumstances, we may take Alchimilla 

 vulgaris and A. alpina, the first of which grows in our plains, 

 and the last on our mountains. So long as they were observed 

 in such different places, a common origin might be attributed to 

 them, their specific differences being explained by the different 

 circumstances under which they grew. But M. Bravais, who 

 at one time entertained this opinion, has abandoned it ever since 

 he found both plants growing together in Lapland, in a place 

 where they had existed probably for centuries, but without in 

 the least losing their respective peculiarities. 



Article 2. 



Modifications of Organic Forms. 



When it is considered how much a living body, with however 

 little complexity of organization, depends on certain conditions 

 of the external world, such as temperature, light, moisture, 



VOL. VI. G 



