468 Mr. R. M‘Lachlan’s Observations on Lepidoptera. 
quainted with the American species of this group, he would have 
laid more stress on it to illustrate his views. 
In taking leave of this subject, I tender my sincere thanks to 
Mr. Hellins and Mr. Buckler for their kindness in assisting me 
with notes. 
be distinctly understood that I am directly opposed to the view held by some 
Entomologists, that these cognate forms are immediately occasioned by the 
difference of the food-plant, though they may have originated from that cause, 
and are thus what Mr. Walsh terms ‘‘ pbytophagie species.”’ 
EXPLANATION OF PLATE XXIII. 
Fig. 1. Sterrha sacraria, 9; the parent of the following :— 
la. Larvee of S. sacraria ; on Polugonwm aviculare. 
2—7, Varieties of S. sacraria, bred from eggs laid by fig. 1. [Unfor- 
tunately, Art has failed to re-produce the beauty of Nature. ] 
