144 ERNST HAECKEL. 



authority, representing the simplest facts to he highly 

 complicated, the homogeneous as heterogeneous, and those 

 closely allied as being very far apart. His highly ob- 

 scure and confused bundle of thoughts, both on embryo- 

 logicil and histological subjects would doubtless be very 

 quickly indeed forgotten, were it not that he knew how to 

 envelope them in a parti- coloured covering of bombastic 

 phraseology, garnished with an edging of philosophical tech- 

 nical terms, and by such a mantle to hide the emptiness that 

 prevailed within. Although a few were thereby truly deceived 

 and allowed an admiring acknowledgment of his confused 

 opinions to overcome them, yet these were themselves very 

 soon shown up in their true emptiness by Baer, Rathke, 

 Remak, Bischoff, Carl Vogt, and others ; and thereby only 

 showed the more clearly the fundamental security of the 

 germ-lamella theory which Reichert had in vain sought to 

 destroy.^ 



Just one hundred years elapsed from the appearance of the 

 * Theoria generationis ' when the history of development 

 received an impulse which gave a new direction to the beaten 

 path. In 1859 Charles Darwin published his epoch-making 

 work on the Origin of species, which, by the theory it con- 

 tained of Natural Selection, brought about a highly fruitful 

 reform of the theory of descent. This latter theory had 

 already been put forward in 1809, by Jean Lamarck, in his 

 deeply-meditated ' Philosophic Zoologique,' with full con- 

 sciousness of its importance as a true basis of thought where- 

 with to found a Biological Philosophy ; but it was even with 

 it as with Wolff's equally important ' Theoria generationis,' 



* In historical reviews of the subject of the development of organic 

 bodies, one will frequently find mentioned with the names of Wolff, Baer, 

 Hemak, &c. &c., also that of Reichert, as one of the meritorious promoters 

 of this subject. This can only be understood to mean that Reichert 

 contrived through his completely erroneous and unsubstantial views 'of the 

 subject of development, and by his trifling, pretentious essays, to bring 

 about a powerful reaction. Just as in histology he helped not a little to 

 strengthen the protoplasm theory by his strange attacks upon it, so also 

 has he in a manifold manner, though indirectly, furthered scientific 

 embryology by his incorrect doctrine of " enveloping membranes," by his 

 untrue "laws of formation," and by his completely erroneous views of 

 histogenesis. But there is no reason why, for all this, his negative services 

 should be compared with the positive ones of Baer, Rathke, Remak, and 

 the others, who have also energetically guarded themselves agaiust such. 

 There are, indeed, among Reich ert's extensive embryological investiga- 

 tions some few useful observations (even a biiird hen will sometimes stumble 

 on a graiu of corn), but, in the gross and on the whole, they are to be classed 

 as works of the lowest class, and to be grouped with those by a Donitz, 

 Dursy, His, and the like. A few significant ideas, which Reichert parades 

 as his own, he has only borrowed from Rathke and others. 



