78 Miscellaneous. 



We might instance the tapirs, swine, and some deer (all branches 

 of the early trunk of the Ungulata), which in their youthful stages 

 exhibit spotting, which afterwards is relatively effaced with 

 increasing age. 



Kespceting Atavisim, or Apparent Reversion, in the Equidae, he 

 refers to the ancestral dentition, to the five-toed ancestor, to occa- 

 sional instances of cleft hoof, to at times a complete ulna in recent 

 horses, as taking after the prototype of ancient equine forms. He 

 instances Prolohippus and Hipparion^ the former as the ancestor of 

 the breeds of horses, the latter as common ancestor of asses and 

 zebras, without giving any decided data thereon *. 



Eeference is made to Mr. Bateson's f limits of reversion getting 

 credit for things sufficiently accounted for by variation. Nevertheless, 

 Prof. Ewart says : — " The heredity problem is sufficiently difficult 

 as it is, but if we are debarred from invoking the assistance of the 

 reversion hypothesis, it will become hopelessly incomprehensible." 



In substance he most justly observes that preponderance is giveo 

 to the colour of the dermal system in experiments as bearing on 

 reversion, while habits and general structure only occupy the back- 

 ground, Notwithstanding this cautious advice the author himself 

 has fallen into the trap, though he has endeavoured to relieve the 

 situation by sundry brief notes on (he tempers and habits of some 

 of his hybrids. But the fact is, coloration, and especially zebrine 

 stripes, can be reasonably compared, whereas temperament and, neces- 

 sarily, habits are physiological factors of uncertain value on which 

 to base comparison. 



To sum up : whatever the ultimate result of Prof. Ewart's experi- 

 ments, it would seem as if we h;id advanced a short stage in the 

 matter of Telegony and Reversion, though some of his deductions 

 doubtless will be questioned. The researches so far are still in the 

 initial stage, but they are a stimulus, and it is to be hoped may be 

 further pursued. Finally, where is the index ? — a marked omission 

 in this volume — for the brief table of contents does not help much 

 where direct references on special points are needed. 



MISCELLAXEOUS. 



On Evdysis in Insects, considered as a means of Defence against 

 Animal or Vegetable Parasites. — Special Holes of the Tracheal and 

 Intestinal Ecdyses. By J. Kvnckei, d'Heucclais. 



Br the experiments made by us in Algeria for the purpose of en- 

 deavouring to infect young Acridians (migratory locusts) by means 

 of spores of the fungus that we discovered upon the adults — the 



• For an excelleut epitome of 'The Horse,' bis ancestors and living^ 

 relations, clothed in most popular language, commend us to Flower's 

 volume, ^^ith its reference to the palaontological and other literature of 

 the Equidaj. Tegetmeier and Suthorland's ' Horses, Asses, ZebrJUs, and 

 Mules, and Mule Breeding ' (1895) may al^o be profitably consulted. 



t See his ' Materials for the Study of N'ariation,' 1894. 



