56 
MIMULUS SM1THII. 
for some time, and have reached that stage of existence when they assume one of 
their metamorphoses.” 
A leaf of the Sarracenia Jlava , now before .me, and from which the sketch was 
taken, contains no less than thirteen flies, principally the blue-bottle fly, ( Musca 
vomitoria ,) with two or three of the common house fly ( Musca domestica). I 
have frequently observed the former of these species, after having penetrated some 
distance into the tube, struggling in vain to extricate itself ; but no sooner had I 
enabled it to escape, than it flew off with its wonted strength and activity. Now, 
supposing it possible that any species of the sphex or ichneumon, which are occa- 
sionally observed in hot-houses, should possess the strength necessary to compel 
the common house fly to enter the tube, contrary to its inclination, it is far 
beyond the reach of probability to imagine that it could oblige the blue-bottle to 
do so ; and however easy it may be for the ichneumon to deposit its eggs in the 
sluggish caterpillar, it could by no means deposit them in the body of this strong 
and restless insect. But, if the flies are not deposited in the tubes of this plant by 
these insects, what is it that induces them to enter? Possibly, as suggested in 
Kirby and Spence’s “ Introduction to Entomology,” the effluvia emanating from 
putrid animalculse, in the lower part of the tube, may induce the flies to enter in 
search of a' fitting receptacle on which to deposit their eggs, or they may enter in 
quest of food ; but whatever be their inducement, repeated observation has convinced 
me that their ingress is voluntary ; and having descended some length, the gradual 
contraction of the tube, assisted by the short stiff hairs which clothe its inner 
surface, and which point downwards, effectually prevent their return. 
These observations render it unnecessary for us to say much more relative to 
the Sarracenia. We might just add, however, that some pitchers which we 
examined the other day, on plants in our possession, contain flies of a large size, 
which must have crawled down of their own accord, since, from their position on 
the sides, not having reached the bottom, it was evident they w T ere walking down, 
and could not have been violently thrown in by any other insect. We also saw a 
large wood-louse ( oniscus ) which had not reached the bottom. May not these 
have been allured by the sweetness found on the edge of the pitcher ? particularly 
on that part of the S. andunca ? This seems to have been the opinion of Macbride ; 
the water, however, at bottom is often very offensive, which no doubt arises either 
from the putrid insects, or stagnation, or both, as we could not perceive any 
smell in those just opened, where no insects had made an entrance, and the water 
was fresh, nor had it any unpleasant taste. 
Culture of Sarracenia. — The usual mode of culture practised at Chats- 
worth is to plant them in pots filled with turfy peat, mixed with small pieces of 
freestone to keep the soil very open ; the pots are then plunged in sphagnum, or 
placed in pans of water. During the summer months they stand in a frame placed 
on a north border, and in winter we keep them in the green-house. S. variolaris 
