224 • [March, 



as iu Phylloxera quercus. The sexuated individuals copulate in 

 the spring, and the female deposits a single egg, which endures 

 through the year, and gives birth to the agamous stem-mother only in 

 the following spring (we find here again the error committed by Bal- 

 biani of giving the time of appearance as a character — Balbiani says 

 "ceuf d'hiver" for the Phylloxera, and Derbes has " aile d'automne" 

 and "aile du printemps " for the Pemph. cornicularius, ^'C^oVi^'wx 

 insects having such a complicated generation as the plant-lice the same 

 forms can appear at any time of the year). 



C. V. Riley, of St. Louis, says of Schizoneura uhni that "it curls 

 " up the leaves in spring, and the winged females (my pupiferous 

 "form) resort to the bark and bring forth the -sexuated individuals, 

 " which are bark-suckers, and lay the winter-eyg (thus also using the 

 " objectionable term of Balbiani) under the bark." Eiley does not 

 believe the insect to be subterranean in any stage of its life. 



Rudolph Leuckart, of Leipzig, has also observed the sexuated 

 form, unwinged, without rostrum, of Pemphigus sph'othecce. 



And to-day, I find here, under the bark of elm {Zflmus campestris), 

 the sexuated female of Tetraneura uhni, dead, close to an enormous 

 single egg, from which, undoubtedly, will come the stem-mother, which 

 has to form the galls in the spring. How happy would poor old 

 Freiherr von GTleichen be, if he were still alive (he died in 1783), to 

 hear that the male form of Tetraneura uhni for which he looked day 

 by day during eight years, has been found, and that the cycle of life, 

 of which he described the gall-period so accurately, is now entirely, or 

 at least very nearly, known. 



Waiting for further information, I only give here the following 

 indications as means to guide those entomologists who would like to 

 discover one of the yet unknown forms of a very common insect. 

 Under the bark, or in the crevices of the bark, of the elm, principally 

 stunted shrubs ("rabougris "), I find a dry, apterous, little female louse 

 of 0.41 mill., 'Without rostrum, and having short, 4-jointed antennic ; and 

 close to her a large egg of 0.35 mill, tlius nearly as large as the 

 mother, I hope to be able to follow up observation of the further 

 stages of life of this insect. I also now find, at liberty, as many eggs 

 of Schiz. corni as I like, but as they are not in a condition adapted to 

 my theory, I ffeserve further communication respecting them for 

 another number of this journal. 

 MoiitpclUcr : \Qth January, 1878. 



