THE PHASMIDS. 



129 



classic instance of adaptation to environment, the slender apterous 

 forms resembling twigs are so well-known that they have given the 

 popular name to the group. The stalwart, spiny Eurycantha, the 

 delicate and beautifully coloured Necrosiidae, are as fascinating as the 

 better known stick and leaf mimics, and the unending variety of form 

 in the ova make an additional incentive to the study of this group. 

 But, in spite of this variety of interest, the labours of many capable 

 entomologists, spread over a century, have failed utterly to establish a 

 satisfactory and natural classification. This failure is due to two 

 difficulties inherent in the study of the Phasmids, first, the extreme 

 dimorphism of the sexes, and secondly, predominance of characters 

 acquired by the development and adaptation of the species over the true 

 phylogenetic characters. The sexes are often so different, that males 

 and females have often been placed in separate genera (Asprmas, 

 Heteropteryx, Monandraptera, etc.). The second difficulty has resulted 

 in the placing in the same genus of species really widely removed 

 (Asprmas, Raphiderus). The earlier authors— Serville, Burmeister, 

 and others — contented themselves with purely empirical characters, 

 such as the dilatation of the feet, length of the thorax, and presence 

 or absence of wings. In 1859, Westwood published a catalogue of the 

 Phasmids of the British Museum, in which he described and illustrated 

 numerous species, but he failed utterly to establish a satisfactory 

 system. A glance at his splendid drawings shows at once, as Brunner 

 has pointed out, that totally distinct forms are frequently arranged in 

 the same genus. In 1870, de Saussure remarked on this unsatis- 

 factory arrangement, but was unable to make any improvement. It 

 was not until Stal attacked the family, in 1875, that any real progress 

 was made, and here, for the first time, we find a number of fresh 

 characters employed. In 1893, Brunner gave us an outline of the 

 modern system, which is now at last elaborated in this splendid work. 

 No one will refuse full credit to the sagacious Swedish author, 

 but the most experienced entomologist will be unable to use Stal's 

 papers for systematic work, owing to the want of clearness and 

 precision in his synoptical tables. This explains the lack of success 

 in the works of Wood- Mason, Kirby, Scudder, and others, and the 

 difficulty was only overcome by Brunner, thanks to his possession of 

 his types. With the highly capable assistance of Professor Josef 

 Redtenbacher, Brunner devoted many years to the herculean task of 

 producing a complete monograph of the extensive and fascinating 

 group of Orthoptera, and the first part of the fruit of their united 

 efforts has at length appeared. The first character employed is the 

 presence or absence of a small, elongated, and very distinct triangular 

 area at the extremity of the underside of the tibia?. This character 

 can have little effect upon the bionomics of the insect, and is regarded 

 by Brunner as a relic of some lost organ, a legacy of the remote past, 

 which has no bearing, beneficial or the reverse, upon the present 

 life of the insect. This forms a distinct line of systematic cleavage, 

 and permits the Phasmids to be divided into two great groups — the 

 Anarcolatae and the Areolatae. In this monograph, Brunner has 

 confined himself to the Anareolatae, that is, the Clitumni, Lonchodini, 

 Bacunculini, and Neci'osiini, his colleague, Redtenbacher, taking the 

 Areolatae, that is, the remaining families. A second character, like- 

 wise first employed by Stal, is the extent of the median segment. 



