262 ANNUAL OF SCIENTIFIC DISCOVERY. 



between pachydermata and solipedes, which latter were consid- 

 ered perfectly distinct so long as the genus equus was character- 

 ized by a single linger at each foot. Now, Mr. Owen, on examin- 

 ing the horses' teeth found in the cavern of Oreston, discovered 

 that the equus plicidens to which they belonged was intermediate 

 between the hipparion and the present horse. In the equus pli- 

 cidens the enamel of the teeth presents more folds than in the liv- 

 ing breed; but in the molars found in our gravel pits, M. Gaudry 

 has perceived gradations between those presenting many and 

 those presenting fewer folds, whence he concludes that our horse 

 is a descendant of the equus plicidens. A hippopotamus, the re- 

 mains of which were discovered at Grenelle a few years ago, 

 appears not to differ materiall} T from the race that now inhabits 

 the rivers of Africa ; and j'et at the time this animal was disport- 

 ing himself in the Seine, the climate was much colder here than 

 it is now ; so that M. Gaudry concludes with great plausibility 

 that, if we had the whole skeleton, some differences would prob- 

 ably appear. Scientific American. 



DARWIN'S THEORY. 



Bischoff, in a recent work on the comparative anatomy of the 

 quadrumana, appends a note on the Darwinian theory, some of 

 the points of which are as follows : 



The assertion that the anthropoid apes are the direct ancestors 

 of man, even if it were supported by any evidence, is contrary to 

 the Darwinian theory rightly understood, for the extinction of the 

 parent form is the direct consequence of the development of an 

 improved form. The problem of organic nature is twofold: 1. 

 The origin of the simplest original forms. 2. The causes and the 

 mode of their operation, by which more perfect forms were devel- 

 oped. A great defect of Darwin's theory is, that he leaves the 

 first question unanswered. Admitting that certain organisms 

 must have been created, what right has he to say that other organ- 

 isms may not have been created at intervals, even to the present 

 time ? Another defect of the Darwinian theory is, that no cause 

 is assigned for the commencement of variation. To say that or- 

 ganisms have at once the power of transmitting peculiarities by 

 inheritance, and of spontaneously originating varieties, is a con- 

 tradiction in terms. Darwin's treatment of the second half of the 

 second question is more successful. Natural selection and the 

 struggle for life must henceforth be fundamental principles in any 

 theory of development. Since no general cause is assigned either 

 for the origin of life or for the commencement of variation, all 

 that can be considered as proved is, that certain forms have been 

 produced by variation from certain other forms. The facts war- 

 rant no general deduction. American Journal of Science, July, 

 1867. 



THEORY OF THE SKULL. 



Mr. H. Seeley thus concludes a paper on this subject: "The 

 skull is the terminal segment of the body; and, just as the adja- 



