224 Observation of the Origin of Varieties. 
lariaccac, 1 and of many other families, especially or- 
chids. 2 The relation between this position and the reg- 
ular form of the flower is still without a proper explana- 
tion; and the question whether the anomaly is due to 
high nutrition or to the absence of the factor which 
determines the bilateral symmetry or both, still awaits a 
definitive answer. Laterally situated peloric flowers are 
very rare but sometimes occur as we have seen in Linaria 
Fig. 43. Antirrhinum ma jus. A, Peloric flower from the 
middle of an otherwise normal raceme, August 1899. 
Two slips of the corolla stand erect ; the other three are 
bent downward. B, Normal flower of the same spike. 
vulgaris hemipcloria (Fig. 41, p. 207), and as is shown 
by Antirrhinum majus (Fig. 43), etc. Of great impor- 
tance, also, is the hitherto little noticed fact that in Digi- 
talis and one or two other cases, the peloric terminal 
flower opens first of all, whilst the order of opening of 
all the other flowers on the stem is normal, i. e., aero- 
petal. 
1 EICHLER, Bliithendiagramme , I, p. 208. 
2 PFITZER, in ENGLER and PRANTL'S Naturl. Pfiansen-Familien : 
Orchid., p. 61. For further information on pelorias of Orchids see 
PENZIG, Mem. Soc. nat. Sc. Cherbourg, Vol| XXIX,, 1894, pp. 79-104. 
