Silk Manufacture. 79 



lay among the grass, without making a finished nest, which 

 soon disappears beneath the quantity of eggs. The same 

 color is also remarked among several birds, which quit their 

 eggs when they lay them, but which are attentive in watching 

 them, as swans, ducks and geese. The eggs of certain great 

 birds which make their nests in the open air, but are well 

 able to defend themselves, are a dirty while, as may be ob- 

 served among the vultures and eagles. Among the eggs of a 

 mixed color, they are to be distinguished which have a white 

 ground, and those of which the ground differs from white. 

 Most of the eggs with a white ground are concealed in well 

 covered nests. 



With all due deference, however, to M. Gloger, we would 

 remark that the theory appears to us much more beautiful 

 and ingenious than true; for we could enumerate more instan- 

 ces in which the principle fails than holds good. If we ad- 

 mit that the brightest white eggs are to be found in birds 

 whose nests are the most concealed, may we not rather infer 

 that, because the interior of these nests is peculiarly dark, the 

 bright white color is convenient to the bird, to enable her to 

 distinguish them ? At all events, we must regard M. Gloger's 

 hypothesis as ingenious, rather than supported by facts. 



CABINET CYCLOPAEDIA. 



SILK MANUFACTURE. 



NO. III. 



Culture of the Mulberry. * The first object of atten- 

 tion, preparatory to any extensive attempt for the production 

 of silk, must be the culture of the mulberry tree, the leaves 

 of which form the sole subsistence of the silk worm. 



'This tree, the JWorws of botanists, is a genus of the tertran- 

 dria order, belonging to the monoecia class of plants. Lin- 

 naeus enumerates seven distinct species of the mulberry 

 tree. 



♦ The Nigra, or black-fruited species, is well known in this 

 country, and much prized for the fruit which it so abundantly 

 bears. Any particular description of it here would be super- 

 fluous. 



' The Alba, or white-fruited mulberry, differs from the nigra 

 in having its stem straighter, and its bark smoother, and of a 

 lighter color. Its leaves are likewise smoother, thinner, much 



