1899-1900.] Dr E. Stewart MacDougall on Genus Pissodes. 331 
were the result of eggs laid in the same year ; indeed, they are 
likelier to have been beetles from larvae which overwintered as 
such. Besides, even if for the sake of argument we admit that the 
June beetles were from eggs of the same year, Henschel takes for 
granted that the so-called summer generation is able to proceed at 
once to reproduction, a fact which has still to he proved. 
2nd. The generation is a single or annual one. — Eatzeburg, Hitsche, 
Altum, Pauly, and Perris all favour the one-year generation (while 
also admitting the additional possibility of three generations in two 
years), although there is some difference of opinion as to the details, 
Eatzeburg holding it to be the general rule that the winter is 
passed in the imago stage, while Perris, writing of his observations 
in France, stands out for hibernation in the larval stage. 
Thus Eatzeburg : (6) “ Die Generation ist auch meist nur eine ein- 
jahrige hochstens dann und wann eine anderthalbige, gewiss nie eine 
doppelte. Die Kafer im Nachsommer oder Herbst ausschliipfen, 
iiberwintern und sich im Friihjahr begatten, so dass man die Brutt 
im Laufe des Sommers sich vollstandig his zum Kafer entwickeln 
sieht.” 
And Perris : (7) “ Ordinairement le P. notatus hiverne a l’4tat de 
larve. Celle-ci se transforme en nymphe vers la fin du mois 
d’avril ou dans le mois de mai et comme l’etat de nymphe dure 
environs un mois et qu’il faut ensuite a l’insecte parfait un certain 
temps pour fortifier ses organes, durcir son enveloppe pratiquer une 
ouverture dans la couche de fibre ligneuses qui formait sa niche et 
percer enfin le bois on Fecorce qui Fabritait il en resulte que les 
Pissodes ne se montrent guere que vers la fin de Juin.” 
The seeming contradictions are really no contradictions at all. 
The facts are correct, hut the generalisation is wrong. 
The key to the whole position lies in the proof, given by the 
experiments, of the long life and long-continued egg-laying of the 
mother beetles which make it possible to find notatus, at the same 
time, in very different stages of development. During my experi- 
ments I have found with Henschel, imagos in June and August ; 
with Eatzeburg, larvae in summer and hibernating imagos ; with 
Altum, imagos in May and August ; with Perris, hibernating larvae, 
and imagos in June and July. 
On one and the same day and near one another it is possible to 
