2(\ HOW IM ANTS I S1-: ANIMAL?;. 



and beyojul die An-tic circk'.* 



As tnis in ihe species to which Darwin has devoted 277 

 pages of his interesting work on insectivorous plants, in which the 

 reader can obtain a remarkable amount of information respecting 

 its movements and digestive powers, a brief description will be 

 sutticient here. It is a small herbaceous plant, five to eight 

 inches high, growing generally (not always) in sphagnous bogs 

 where its roots cannot reach ihe barren soil below; the mosses 

 themselves depend upon the atmosphere and the rains for their 

 nourishment. Its roots are few and small and seem only to 

 absorb water. The leaves are reddish, and form a cluster around 

 the base of the scape; they are nearly orbicular in form and 

 taper abruptly into the petiole. In their young condition, they 

 are rolled up from tlie apex to the base. Their whole upper 

 surface is beset with glandular hairs or tentacles, which are 

 usually tipped with a small drop of a viscid secretion, glistening 

 like dew in the sunshine, whence it receives its name. The 

 slender, naked scape bears the small, white flowers "in a one- 

 sided, raceme-like inflorescence, which nods at the undeveloped 

 apex, so that the fresh-blown Hower, which opens only in the 

 sunshine, is always highest." (Gray's Manual.) 



Darwin counted the number of glandular hairs, or tentacles, 

 on thirty-one leaves and found the average number was 192; the 

 greatest number being 2B0, and the least 160. Ihose on the 

 central ])art of the leaf or disc are short and stand erect; those 

 on the extreme margin project on the same plane as the leaf, or 

 are more commonly reflexed. When an insect, or any small 

 object, comes in contact with the central tentacles, a motor 

 imjiulse is transmitted to those around them and is gradually 

 l)ropagated to those placed on the maigin. The nearer ones, 

 being first affected, begin to bend toward the centre — then those 

 farther off', until all become clo.'sely inflected over the object. A 

 living insect is much more effective in producing movement than 

 a dead one, as its struggles bring it into contact with a greater 

 number of tentacles. The length of time required for complete 



*Mtic-<mn, (!at[:logiie of Canadian Plants. 



