1917] 
BRYAN—HABENARIA 41 
Orchis and Habenaria the lip is prolonged baekwards into a 
spur, which adds further to the irregularity. Through the 
loss of a spur or of other irregularities, the flower may assume 
a regular form. Cases have been recorded also of three- 
spurred orchids. Hill! describes H. lacera var. as having three 
spurs and two lips, and one of the lips again dividing as if to 
maintain the tri-formity. Two columns were also present. 
Cases of false peloria have also been found in which two ex- 
tra spurs were produced by the lateral sepals and not, as in 
cases of true peloria, by the lateral petals. Abnormalities such 
as these are especially interesting in the case of the orchids. 
The pelorias consist chiefly either in the loss of the spur, or 
else in an increase in the number of spurs to three. In either 
ease this tends to make the flowers pass from zygomorphy to 
aetinomorphy, and the latter condition is probably more 
primitive than the present irregular form. Regularity must 
be a latent yet heritable character in orchids, and the loss 
of it in this extremely complex and highly differentiated 
family is only apparent, since it shows a not uncommon 
tendency to return to its full activity in these peloric forms. 
Our concern is whether this latent character has returned to 
activity suddenly, or whether by a slow and gradual recovery 
of the former features. Pelorism is a phenomenon where 
the eapacity to form irregular flowers has been reduced to 
a latent or inactive state. Conditions of nutrition are thought 
to be the external cause in inducing the appearance or non- 
appearanee of the monstrosity. 
Hundreds of steps have probably been necessary in the 
evolution of the orchid family. The variety with which we 
are now concerned, therefore, and others, may be considered 
as a reversion toward an ancestral condition on the part of 
the species exhibiting it—a reversion which seems an offset 
to the extreme specialization to which orthogenesis or adapta- 
tion has led the family. Monstrosities as commonly under- 
stood are now generally regarded as visible manifestations of 
a heritable, though for the most part latent, potentiality, and 
are retrogressive phenomena. 
1Bot. Gaz. 15:145. 1890. 
