162 



EGGS OF BIRDS. 



variety of experiments we have tried on various birds, amongst 

 which was the swallow, which has been declared to lay as many as nine- 

 teen. 1 A bird will only lay the usual number peculiar to the species ; 

 and if, at the period of incubation, it perceives the nest emptied, it is 

 deserted. The link of nature having- been broken, the female stimulates 

 to love again, and soon brings forward by that stimulus, aided by the 

 male fecundity, a new lot of eggs ; never more than the former, and 

 usually less, because this is properly a forced production, at the addi- 

 tional expense of the vigour of the bird, and loss of animal parts, which 

 is the cause of a great variation as to the number of eggs laid by domestic 

 fowls, depending entirely on the strength of the constitution, and the 

 nourishment of the food. In all animals taken immediately under the 

 care of man, the dictates of nature are partly suppressed, their food 

 changed, habits and manners altered, and disease often ensues, which is 

 the origin of the great variety of colours in reclaimed animals. 



Nature pursues invariably one course ; therefore to draw a general 

 rule of her actions we must strictly adhere to her in an unmolested, 

 uncultivated state ; for if we deviate from that we must infallibly err. 

 We do not mean to say accidental varieties do not take place in animals 

 unreclaimed, but such lusus are by no means common ; and when we 

 see a bird materially deviate in colour from its species, we may consider 

 it as a constitutional defect, that the natural secretions are changed or 

 suppressed with which the feathers are dyed. To enter minutely into 

 a discussion on this head would swell this article beyond its limits ; 

 all we wish is, to point out the necessity of strictly adhering to nature 

 for observations on natural causes. A domestic fowl, who will sit for 

 six weeks upon an empty nest, is not to be produced as a proof of the 

 actions of nature. Will any bird, in its natural wild state, continue to 

 sit on its nest after the eggs are taken out ? One egg, indeed, is some- 

 times sufficient to produce the act of incubation ; but what is it then that 

 prevents the secondary eggs from coming forward, when it is well known 

 if a bird is prevented from sitting, she soon resumes her desire of 

 propagation natural to every animated being ? Because the very act of 

 incubation is the effective cause ; the line which nature has drawn, and 

 which the animal by instinct feels. We conceive the production of a 

 second lot of eggs to be an extraordinary exertion of nature ; a wonder- 

 ful proof of the affection of the all-wise Creator for the preservation 

 and continuation of his creatures, and the resources he has furnished 

 some animals with, in case of necessity, to prevent the total extinction 



1 An assertion of Dr. Lister. Vide Br. Zool. p. 337. 



