450 Dr. A. Dohrn on Eugereon Boeckingi 



moutli. If we suppose the labial palpi to lay themselves to- 

 gether by their free, smooth, inner margins, and to enclose 

 the jaws within them, we have before us a picture exactly 

 analogous to the rostrum of a Bug, All that would then be 

 necessary is the amalgamation of the two palpi so as to pro- 

 duce the tube, and the gradual conversion of the rather stronger 

 jaws into weaker ones, to attain the formation of the Hemi- 

 pterous rostrum. The structure of the head, the breadth of 

 the thorax, the form of the legs, which so distinctly remind 

 us of the Fulgortda;, are, moreover, the clearest indications that 

 we have to do with an animal which is very nearly allied to 

 the Hemiptera. On the other hand, however, the form of the 

 wings, the venation, and the antennas do not altogether nega- 

 tive a comparison with the Neuroptera ; and thus we get as 

 the probable final result that Eugereon is to be regarded as a 

 very ancient insect, which indicates a still older progenitor, 

 in which Hemiptera and Neuroptera were still entirely undif- 

 ferentiated. It would be impossible to regard Eugereon itself 

 as this progenitor, because, in the first place, Neuroptera were 

 already in existence along with it, their remains having been 

 found ; but, on the other hand, we can hardly fail to see how 

 it would gradually entirely lose the characters of the one order 

 and change and bring to perfection the others alone. It is 

 much more intelligible to regard it as part of an extinct side- 

 line, which had a common progenitor with the Hemiptera and 

 Neuroptera, if, indeed, my view as to the relationship of 

 Eugereon with the latter order in the structure of the wings 

 and antennae should prove correct." 



Thus, therefore, we have in Eugereon an animal which 

 again demonstrates with extraordinary distinctness the truth 

 of the Darwinian theory, and does its part in assisting to throw a 

 little more light upon the principles of morphological science. 

 It was to be expected, and, indeed, was regarded as certain by 

 all unprejudiced naturalists, that morphology in general would 

 undergo a powerful shock and a complete revolution by means 

 of the Darwinian theory, and that a gigantic step would have 

 to be made in this science. Already, before any one could 

 have expected such a thing, this gigantic step has been made 

 by Hackel, the celebrated zoologist of the University of Jena. 

 In his work on the general morphology of organisms* are 

 laid down the principles of a new science. Morphology. I 

 shall have occasion elsewhere to refer fully to the wide signi- 

 ficance of this work, and its extremely rich and many-sided 

 contents; here I will only extract one thing, namely, the 



* Generelle Moi-pliologie der Organismeu, von Ernst Hackel. 2 vols. 

 Berlin, 18G6. 



