280 ANNUAL OF SCIENTIFIC DISCOVERY. 



The ogjr is regarded as an animal from the first, ])ut comparable 

 only to the lowest forms of infusorial life. T]u3 continued devel- 

 o]iment of the egg, or embryo, is shown to depend more or less 

 upon secondary caus(\^, — most so in the lowest animals, — and 

 in this resjject ii comparison is made with those <^erm-like foiins 

 supposed to originate and develop wholly through secondary 

 causes. 



He adopts the four gi'and divisions of Cuvier, "with modifica- 

 tions ; and, willi many others, believes Uiat tiie Protozoa consti- 

 tute a fifth division, as distinct from the others as those are among 

 themselves; but lie regards tiiem as merging gradually into each 

 other, as clouds tliat touch and mingli- sonu'wliat at tiieir ijorders. 

 The bipolar relations in tlie organization of all animals, and the 

 bilateraHty which is equally a fundamental feature of all, are 

 illustrated; and it is shown that this is as characteristic of Radi- 

 ata as of tlie higher grouj)s; and it is claimed that the nKU'c or 

 less radiated appearance is subordinate to bilaterality. The char- 

 acteristic featiH-e of Protozoa is stated to be; spirality or ol)li(piity, 

 sui)erimposed upon bilaterality. The Radiata are said to have 

 *' a type of organization in wiiieli the various organs repeat them- 

 selves, more or less, between the back and tlie abdominal mid- 

 line of the body ; that is to say, they are laterally repetitive on 

 each side of an imaginary plane wiiieli divides the body exactly 

 into rigiit and left halves.'' The Mollusca are compared in a 

 similar way to tiie other groups, thus: " The Zoophytes are from 

 back to front, dorso-ventrally, polymerous; the Articnlata are 

 from tail to head, in-o-cephally, jjolymerous ; and the Mollusca 

 are monomerous." IJy detaileil comparisons, it is shown that there 

 are no actual transitions from one of the five great divisions to 

 another ; and that each has a distinct and characteristic mode of 

 development and growth. — Amer. Jour, of Science, May, 1866. 



SPONTANEOUS GENERATION. 



A contest has been long going on between French savants on 

 the question' of spontaneous generation, some of the points of 

 which have been alluded to in the " Annual of Scientific Discov- 

 ery," for 1865, page 330, — those on the one side maintaining the 

 questionable doctrine of spontaneous generation, whilst the cham- 

 pions on the other side hold that, under existing conditions, no 

 organism comes into being without the previous existence of some 

 other organism. 



The French Academy appointed a Commission to endeavor to 

 arrive at some settlement of the question, either by establishing 

 heterogenesis (as the old doctrine is now called by its advocates) 

 on the footing of an acknowledged fact, or finally consigning it to 

 the gi-ave of exploded theories. From an elaborate report, com- 

 municated in 1865, by M. Balard, to the French Academy, on the 

 proceedings of this Commission, it would ajipear that, owing to 

 certain difficulties raised by the partisans of heterogenesis, this 

 desirable consummation has not been attained, at least, so far as 

 they are concerned ; although the experiments made in supjjort 



