292 THE ZOOLOGIST. 



the influence of natural selection. Such an investigation has 

 been attempted, and such a result apparently obtained by Mr. 

 Cameron, in his search for "the origin and purpose of the horns 

 and antlers of ruminants." He concludes "that the horns and 

 antlers of ruminants are the result of a defensive adjustment in 

 biological answer to carnivorous teeth and claws, and consequent 

 upon the relations of destroyer and destroyed which obtained 

 between carnivores and ungulates throughout Tertiary time. . . . 

 Their historical appearance in the Miocene age of the Tertiary 

 period is contemporaneous with a vast extinction of hornless 

 ungulate families, and their subsequent development in an 

 ascending scale corresponds with the gradual thinning out of 

 unarmed ungulate genera, and the gradually increasing destructive 

 pressure upon those, whether armed or unarmed, that survived. 

 Their evident loss of calibre since palaeolithic times may be 

 traced chiefly to the coming of man with missile weapons, which, 

 in altering the character of the destroying agency, discounted 

 the value of cranial armature in the struggle for life."* 



It is a remarkable fact with these Phasmidce that giant forms 

 are said to have existed even in the Carboniferous fauna. Among 

 other Orthoptera belonging to that era were " the giant Walking- 

 sticks recently brought to light from the coal-measures of France, 

 the Titanophasma fayoli, which measure in length (in one speci- 

 men) upwards of twelve inches, and are therefore, by linear 

 measure, very nearly the largest of recent as well as fossil 

 insects." f It is necessary, however, to observe that much 

 caution must be exercised in the identification of these fossil 

 remains. Dr. Sharp is at least sceptical, for he writes : — " In 

 the Carboniferous layers of the Palaeozoic epoch there are found 

 remains of gigantic insects that may possibly be connected with 

 our living Phasmidce." j The same writer, however, has sub- 

 sequently given a less undecided opinion : "Phasmidce are insects 

 of extreme interest ; they appear to be the nearest living repre- 



* ' Zoologist,' 3rd ser. vol. xviii. pp. 291-2. 



f Heilprin, ' Geograph. and Geol. Distr. of Animals,' p. 150. — Phar- 

 nacia serratipes, from Borneo, the largest known species, is stated by Mr. 

 Kirby to measure nearly thirteen inches from the front of the head to the 

 extremity of the abdomen (Trans. Linn. Soc. vol. vi. (2nd ser.) p. 448). 



v. p. 276. 



