MISCELLANY. 



251 



like pellicle, resembling cobweb, which be- 

 ing removed, the cocoon is found to be oval. 

 In color it is grayish, and its tissue differs 

 from that of European cocoons in being 

 wove like a bird's-nest. The caterpillar 

 does not shut itself quite up in the cocoon, 

 but leaves an opening, through which it es- 

 capes in tbe imago-shape. 



The Bombyz saturnia works rapidly, 

 completing the cocoon in three weeks ; in 

 three weeks more it quits it ; and thus the 

 silk-harvest takes up only six or seven 

 weeks. The process of filature, or of un- 

 winding the threads of the cocoon, is very 

 simple, the threads, owing to the peculiar 

 structure of the cocoon, being very readi- 

 ly separated from one another by the ac- 

 tion of warm water. The fibre possesses 

 considerable strength. One thread, twelve 

 inches long, will bear a weight of sixty-two 

 grains, and a cord of fifty-four threads a 

 weight of over two pounds. The thread, 

 however, is somewhat coarse, but efforts 

 are being made to get it of greater fine- 

 ness so as to fit it for weaving into fabrics 

 and spinning into sewing-thread. If this 

 Brazilian fibre passes successfully through 

 its period of trial and experiment, it will 

 give the world a very cheap silk, the cost 

 of production being much less than that 

 of European silk. The cocoon is found in 

 great quantities in the north of Brazil. The 

 caterpillar feeds on the tree, and withstands 

 the inclemency of the weather. The tree 

 is so abundant that whole ship-loads of 

 cocoons might be collected. 



The Descent of Man.— M. Gabriel de 

 Mortillet, at the recent meeting of the 

 French Association, after showing that cer- 

 tain flints found in tertiary strata bear evi- 

 dences of human workmanship, goes on to 

 prove that this tertiary precursor of man was 

 not identical in species with the man of tbe 

 present period. " If there is one fact well 

 established," says he, " and admitted by all, 

 it is this: that there is a succession of 

 faunae from one geological period to an- 

 other. From stratum to stratum the fauna 

 is modified, the animals change, and these 

 modifications, these changes, are all the 

 more marked in proportion as the strata 

 are wider apart. Between two strata in 

 contact there may exist species in common, 



but strata widely separated from one an- 

 other have different species, and even dif- 

 ferent genera, in case they lie very wide 

 apart. These changes occur all the more 

 rapidly in proportion as the animals pos- 

 sess a more complicated organization. Thus 

 the mollusca, having a less complicated or- 

 ganization than the mammals, have some- 

 times a far more protracted existence as 

 species. Certain shells are found identi- 

 cal in two strata, in which the mammalian 

 faunae are very widely different. These are 

 not mere hypotheses, but scientific data, 

 based on direct observation of facts. 



"Now, since the formation of the cal- 

 careous strata of Beauce and of the loam- 

 deposit at Thenay, in which chipped flints 

 are found, the mammalian faunae was 

 completely renewed at least three times. 

 The differences between the mammals of 

 the Beauce limestone and the mammals of 

 the present period are not only sufficient 

 to characterize distinct species, but have 

 appeared sufficient in the eyes of zoologists 

 to warrant their classification into special 

 genera. The mammals of the level of the 

 Beauce limestone and of the Thenay loam 

 all belong, almost without exception, to 

 extinct genera — genera nearly allied to 

 those at present existing, but yet quite dis- 

 tinct from them. How, then, could man, 

 who has a most complicated organization, 

 alone escape the action of this law ? "We 

 must therefore conclude that, if, as every 

 thing leads us to presume, the Thenay flints 

 bear the evidences of intentional chipping, 

 they are the work, not of the present hu- 

 man species, but of another species of man, 

 possibly even of a genus the precursor of 

 man, which would serve to fill up one of the 

 gaps in the zoological series." 



An Ancient Papyrus. — The King of Sax- 

 ony has purchased, and placed in the Leip- 

 sic Library, an Egyptian papyrus on the 

 preparation of medicines, which was found 

 at Thebes by Dr. Ebers. It is a beautiful 

 yellow papyrus, in a good state of preserva- 

 tion. It consists of 110 columns, and has 

 written on the back a double calendar in 

 eight columns. Each column is eight inches 

 wide, and contains twenty-two lines. The 

 writing is from right to left ; it »<* all in 

 black ink, except the beginnings ot chapters, 



