Prof. Carl Vogt on some Darioinistic Heresies, 61 



Let us go on. If the ways indicated as those by which 

 the transformations are effected be true, it follows that we can 

 by no means deduce complicated organisms from simple ones 

 which have not even the rudiments of the organs with which 

 the former are furnished. Neither in palaeontology nor in 

 embryogeny have we facts which can demonstrate the acqui- 

 sition of entirely new organs^ while ; on the contrary, there 

 are facts in abundance which prove that the ulterior develop- 

 ment is effected, as we have stated, by losses (limbs, denti- 

 tion), or by excessive development of existing rudiments, or 

 by change of function. 



If we apply these facts to our phylogenetic speculations we 

 must recognize that the latter must be completely reversed, 

 that the less complicated animals owe their existence to a 

 more or less complete retrogradation, and that they must con- 

 stitute the final terms and not the foundations of phylogenetic 

 series. In one word, all our genealogical trees at present 

 accepted must be revised from base to apex so far as they do 

 not correspond with the principles enunciated. 



It is to be remarked that these views square very well with 

 palffiontological facts. We have tortured our minds to explain 

 the presence in the most ancient formations of highly organ- 

 ized types and of what have been in part called collective 

 types, presenting characters oscillating between those of classes 

 and orders now well marked. Cephalopods, Trilobites, 

 Ganoids, and Dipnoids swarm in the ancient formations, and 

 yet these animals belong to the highest types of their respec- 

 tive divisions. They have constituted the stocks of the types 

 which have succeeded them, and their descendants have been 

 formed by the unilateral development of certain organs or 

 rudiments, combined with the retrogradation or the loss of 

 other organs which the stock originally possessed. 



Let us return, in conclusion to our starting-point. The 

 phylogenetic development of the different types has been 

 presented to us in the form of trees which branch as they 

 ascend. Accepting this image, we may say that with regard 

 to these trees our classification plays the part of an espalier 

 to the interspaces of which our divisions into subkingdoms, 

 classes, orders, &c. correspond. The branches of the trees to 

 the right and left which arrive in a compartment thus bounded 

 are definitely classed there, although starting from different 

 stocks. 



