VARIATION AND LOCALITY 123 



ever the species is found. The red form is much scarcer in 

 England, and does not occur at all in many localities where the 

 grey form is common. Mr. Woodforde, from whom this account 

 is taken, 8 states that in August, 1899, he saw considerably over a 

 hundred of the grey in the New Forest at sugar, but only two 

 red ones. In Staffordshire however the red is proportionately 

 more numerous and he estimates them as 40 per cent, of the 

 population. Lastly a form has been taken in Staffordshire as a 

 rarity in which the red is replaced by yellow, and this has hitherto 

 been seen nowhere else. It is beyond our immediate purposes 

 to discuss the genetic relationships of such forms, but the details 

 of this case are interesting as making fairly clear the fact that 

 the distinctions between castanea and neglecta are due to com- 

 binations of the presence of and absence of two pairs of factors, 

 of which one produces a red pigment in the ground colour of the 

 forewing and the other irrorates the same region with black 

 scales. Mr. Woodforde states that all intermediates exist, 

 and that in Staffordshire the greys always have a pinkish tinge. 

 The yellow is doubtless another recessive to the red. 



Species which are uniform in some localities may be poly- 

 morphic in others. Such a phenomenon is well exemplified by 

 the orchid Aceras hircina. Of this species distinct varieties had 

 previously been known in Germany, but Galle 9 has lately given a 

 detailed account of a number of most diverse forms found growing 

 in a district of Eastern France. Without reference to his plates 

 it is impossible to give any adequate conception of the profusion 

 of types which the flowers of the species there assume. In some 

 the lip is elongated to many times its usual length, twisting 

 and dividing in a fashion suggesting some of the strangest of the 

 Tropical Orchids. In others the labellum and the lateral petals 

 are all comparatively short and wide (Fig. 13). Intermediates, 

 combining these qualities in various degrees, were abundant, and 

 the condition of the species, which was the only representative of 

 the genus in the locality, recalls the extreme polymorphism of 

 many of the Noctuid Moths. 



8 Woodeforde, F. C., Trans. North Staffordshire Field Club, XXXV, 1901, Plate. 



9 E. Galle, Compte Rendus du Congres Internal, de Bot. a VExpos. Univ., 1900, 

 p. 112. 



