316 INSECT MISCELLANIES. 



which would never be otherwise developed. I can 

 readily conceive, also, that a habitation, considerably 

 more spacious and differently placed, is absolutely 

 necessary to the complete development of organs 

 which the new nutriment may cause to grow in all 

 directions.' * 



Instances of analogous development, as well as 

 the contrary, might be produced to infinity in all the 

 departments of nature ; though those are perhaps 

 more abundant in the vegetable than in the animal 

 world. We have but small room to spare for illus- 

 trating this, and shall content ourselves with men- 

 tioning a single experiment by Mr T. A. Knight. 

 Wishing to ascertain the effect of stimulating manure, 

 he took a plant of the cockscomb [Celosia cristata), 

 and kept it regularly moist with water, in which 

 pigeons' dung had Ijeen steeped, and at the same 

 time had it successively shifted into larger pots, as 

 the roots reached the sides. The latter, to some, 

 may appear very superfluous labour, as the plant 

 might have been placed from the first in a pot 

 sufficiently large ; but in that case it would have 

 wanted the stimulus arising from the roots impinging 

 on the sides of the pot. The result was, that the 

 plant produced a flower of larger dimensions than 

 had ever been witnessed, t This experiment illus- 

 trates the effects both of stimulant food and space for 

 enlargement. On the contrary, confined space not 

 only retards the growth, but prevents the due deve- 

 lopment of peculiar functions ; in proof of which it is 

 stated by John Hunter, that when a cow brings forth 

 two calves, and one of them is a female, it is always 

 barren. J 



It would be leaving this curious point imperfect, 

 were we not to add to the preceding proofs some of 



* On Bees, p. 56. t Horticult. Trans. 



t On the Animal Economy, p. 65. 



