284 SIR JOHN LUBBOCK ON THYSANURA. 
long que le terminal de l'antenne normale, quoique ayant une forme analogue et la 
méme couleur;. 4”. on n’aperçoit à l'extrémité de l'article aucune trace de fracture 5:41 
plusieurs jeunes Podurides et un. grand nombre d'adultes ont été trouvées ainsi con- 
formées; le nombre de celles-ci était, à l'egard des Ztheocerus à antennes de cinq 
articles, comme cinq est à huit ; 6”. cette conformation des antennes ne se rencontre que 
rarement dans les autres Podurides; 7°. toutes les fois que dans les autres genres on 
trouve des Podurides dont les.antennes ont été brisées, la cicatrice est toujours visible 
et la forme des articles n'a pas varié ; 8°. j'ai renfermé dans des vases une certaine quan- 
tité d’ Atheocerus dont les antennes offraient les différentes conformations observées par 
moi; j'y ajoutai plusieurs congénéres qui avaient ces organes brisés au moment oü 
elles furent trouvées, ou à qui je les avais moi-méme mutilés; au bout de trois mois elles 
furent retrouvées toutes exactement dans le méme état." cuba 
Two years later he repeated this argument in the same words in the Transactions of 
the Soc. d’Agrieult. du Départem. du Nord, at Douai, 1841-2. 
Yet it is, I think, certain that the antennæ of the species forming his genus Æ{heocerus 
(or Heterotoma) are normally six-jointed, although they are very frequently mutilated. 
It is true that in antennæ possessing less than six segments, the terminal one does to a 
certain extent resemble the terminal segment of an unmutilated antenna; but this is 
the case, as I have satisfied myself by repeated experiments in artificially mutilated 
specimens. It is also quite true that the antennæ which are composed of less than six 
segments show no trace of fracture; but it is equally certain that this is also the case in 
mutilated specimens after a change of skin. If one removes part of the antenna of an 
Orchesella, the injury is very apparent until the creature moults, after which the end of 
the antenna becomes more or less regular, according to the time which has elapsed 
between the wound and the moult. M. Bourlet states that this condition of the antennæ 
occurs only among the Heterotome; this, however, is by no means the case. Most of 
the other genera, indeed, having shorter antennee, are less liable to injury ; and mutilated 
specimens are therefore much less frequent among them than in the genus Orchesella. 
Choreutes, however (Macrotoma Bourlet), also has long antennæ ; and here the mutila- 
tions are so frequent that Bourlet actually describes the genus as having three-jointed 
antenne, four being the right number. 1 myself, though 1 have found hundreds of 
specimens, have never found a full-grown Choreutes plumbea with perfect antennæ. 
This almost invariable mutilation is an extremely curious fact. : | 
M. Bourlet affirms that really mutilated specimens always show the “cicatrice.” The 
term is scarcely correct; and, as I have already observed, the mark only remains until 
the next moult. Lastly, M. Bourlet states that, having mutilated the antenns of 
several specimens, and placed them with others in which the antennæ were unsymme- 
trical, he found them at the end of three months exactly in the same condition. This 
statement is quite contrary to my invariable experience, and, unless he tried it in very 
cold weather, he must, I think, have made a mistake. In summer the moults always 
_ follow one another at comparatively short intervals; and at the first moult after mutila- 
tion I have always found a considerable tendency to reparation, which becomes still 
more manifest after two or three changes of skin. oom : 
