Observations on Antidromy. 
By GErorGE MACLOSKIE. 
It was stated in the BuLLeTIn of September and November, 
1895, that every species of flowering plant, including Gymno- 
sperms, appears to havetwo castes of individuals, which are two 
reversed counterparts of each other, as our right and left hands 
are. This ‘antidromic’ diversity is evidently a primitive char- 
acter, and seems to pervade the whole organization of the plant; 
so that when it is masked or disturbed by secondary changes in 
one part we may detect it in others. Thus in Berderis and in 
Cardamine you may find it difficult to determine the antidromic 
phyllotaxy, but the order of flowers in the racemes is manifestly 
antidromic. The opposite leaves of Acer render it difficult to 
trace the right course of the spiral, but here the anthotaxy assists, 
and also in the seedling we are guided by the position of the first 
pair of foliage-leaves relatively to the cotyledons, in some individuals 
crossing somewhat to the right, in others somewhat to the left, 
when the same orientation is maintained. Whether we do or do 
not know the real significancy, the facts themselves are too defi- 
nite to be any longer overlooked; and my present contribution is 
designed to add some new observations which must be taken 
account of as part of the data. 
Erythronium is a good illustration of the unexpected way in 
which the evidence may come up. Hold the plant with the outer 
or sheathing leaf towards you, then some of the plants have the 
solitary flower nodding over to your right, and others have it nod- 
ding to your left. Spring-beauty ( ClaytoniaVirginica) carries the 
same system further, and also introduces an additional factor. 
Hold a specimen with the two fleshy leaves next you, and note 
that the lowest flower arises to your right side from the peduncle, 
the bract arising towards your left side; another specimen held in 
the same way has the first flower on your left side, and order of 
bracts and subsequent flowers antidromic as compared with the 
first specimen. A new point in this is that the same tuber may 
have half a dozen plants, which are half and ‘half of each caste 
according to some definite law. Thus the derivatives of the same 
tuber appear to be relatively antidromic, like the embryos pro- _ 
