Bibliographical Notices. 403 



the contrary, requires absolutely the admission of separate stemmata, 

 certainly for every principal group, apparently and probably so for 

 every genus or natural assemblage of much-resembling forms with 

 similar structures." In the ordinary view, these stemmata, however 

 circumscribed, are regarded as the products of separate creations : 

 in the evolution hypothesis, these forms, " which appear to be, and 

 are really, distinct," are not aboriginal, but the modified progeny of 

 far earlier forms, which, with all the intermediate forms, are utterly 

 unknown to us. "Now," to use Professor PhiUips's words, "they 

 are not unknown to us by any impossibility of being preserved ; for 

 the strata of the Cambro-Silurian series are of a kind in which organic 

 remains of great delicacy are often preserved ; and, indeed, such are 

 preserved in these very strata ; and, by the hypothesis, the life- 

 structures which are lost must have only gradually differed in their 

 nature from those which arc preserved. It follows therefore that 

 the earlier living progenitors of the Cambro-Silurian series not only 

 lived long before, but must have lived somewhere else. But as in 

 all the known examples of this series of strata, wherever found, we 

 have everywhere animals of the same general type, and nowhere the 

 traces of earlier progenitors, it is clear that everywhere we are re- 

 quired by the hypothesis to look somewhere else ; which may fairly 

 be interpreted to signify that the hypothesis everywhere fails in the 

 first and most important step." It may also be urged, to give addi- 

 tional force to the above argument, that the necessity for " looking 

 somewhere else" for the transition-forms is of itself fatal to the 

 hypothesis of evolution : it is quite clear that when new forms make 

 their appearance at a given point, they are (according to the hypo- 

 thesis) either the modified descendants of immigrants from some other 

 point, or of forms previously residing in the same locality ; in either 

 case, the modifications they have undergone must have been intended to 

 adapt them for new conditions of existence at the spot where they are 

 found ; and the intermediate forms should occur, if anywhere, at the 

 same spot. Moreover, when we consider the individual case of Lin- 

 gula, that it is one of the very first known fossils to which we can 

 Avith certainty assign a definite place in the classification of animals, 

 and that it has continued to make its appearance, from the earliest 

 periods down to the present time, with no change except of a specific 

 nature, we may justly ask why, if descent with modification under 

 varying conditions of life were sufficient to produce the type of Lin- 

 ffula in the progeny of the primordial germ as early as the period of 

 deposition of the beds which bear its name, the further influence of 

 at least equal (and most probably far greater) changes in the condi- 

 tions of existence during the long period of time which has elapsed 

 since the appearance of the type of Lingula upon the stage of life 

 should have had so little effect upon it, whilst other types, exposed, 

 as far as we can judge, to precisely the same influences, have been 

 almost infinitely modified ? It appears to us that it is rather too 

 much to expect us, without some evidence or explanation, to assume 

 the occurrence of such phenomena as these ; and the same will 

 apply to the analogous case of the genus Nautihis, and more or lesa 

 to many other forms. 



