G. NATURAL HISTORY AND ZOOLOGY. 281 



the ferment of the former also inverted cane sugar, and also 

 that the gas evolved in fermentation was pure carbonic acid. 

 The mncor-yeast is, however, so extremely sensitive to alco- 

 hol that 3^ to 4 per cent., by weight, of the latter renders it 

 slow and finally inactive, so that it can only be employed 

 when less than 7 per cent, of sugar is present in solution. It 

 does not produce alcoholic fermentation with dextrine, inn- 

 line, or grape sugar. 28 C, April, 1874, 302. 



THE GASTR^EA THEORY OF HAECKEL. 



Professor Ernst Haeckel, in a paper entitled "Die Gastrwa 

 Tlieorie" endeavors to show that the whole animal kingdom 

 above the Protozoa have descended from a simple sac-like 

 form of ancestor, whose body-wall, consisting simply of an 

 ectodermal and an endodermal layer of cells, incloses a space 

 the primitive stomach. This ancestral form constantly 

 shows itself in the development of the most diverse types 

 polyps, sponges, worms, anthropods,mollusks, and vertebrates. 

 The ancestor which possessed this form Haeckel names a, Gas- 

 trwa. All the higher animals are, consequently, Gastixeades ; 

 and though they develop into much more complicated struct- 

 ures than the sac-like Gastrwa, yet they often exhibit a Gas- 

 trula condition in the course of their progress from the ezg 

 to the adult form. In the present memoir Professor Haeckel 

 follows out other questions as to the muscular layers which 

 develop in the higher Gastrceades between endoderm and ex- 

 oderm and the blood-nymph space, or "ccelom," which also 

 makes its appearance in this position. The classification of 

 animals on the basis of these important facts of development 

 is attempted in detail, as well as an enumeration of the tis- 

 sues of the organism according to the mode of their develop- 

 ment. 15 A, February 14, 1873, 220. 



BLEACHING SKELETONS. 



At a meeting of the French society for encouraging na- 

 tional industry, Mr. Cloes stated that in using the essence of 

 turpentine for dissolving the oil of greasy bones, which he 

 was treating for the preparation of skeletons, he found that 

 after an exposure of three or four days in the sun the bones 

 became of a dazzling white. If in the shade, they required a 

 somewhat longer exposure. The articles to be bleached must 



