STRUCTUEE AND BIOLOGY OF SCHIZONEURA LAXIGERA. 655 
For staining sections, liaematoxylin (Ehrlicli), methylene- 
bine, eosin and orang’e Gr have been used. Borax carmine 
was nsed for staining organs in bulk after corrosive sublimate 
fixation. 
Material for sections was imbedded in paraffin wax melting 
at 58° C., for about fifty minutes to two hours, sections being 
cut 6 to 10 ^ thick. Material imbedded in a lower melting- 
point wax (45° C.) gave poor results. 
The drawings have been made with the aid of the Abbe 
camera lucida from dissections, special preparations of parts 
and serial sections through the body. 
III. Systematic Position, Life-History, and Habits. 
Schizoneura lanigera is a member of the order 
Hemiptera, belonging to the family Aphididie, the members 
of which are popularly known as green fly or “plant 
lice.^’ 
It is classified in the group Schizon eurini , of the sub- 
family Pemphigi lue.^ On account of the quantity of white 
waxy threads that individuals of this species produce from 
the dorsal wax-glands they are known as “woolly ajdiis,” 
or “American blight.” This latter term is, however, mis- 
leading, as this pest, according to Theobald (1897), is 
European in origin, and was no doubt impoi-ted into 
America with imported stock. Marlatt (1897, p. 2), on tlie 
other hand, considers that the evidence is in favour of its 
American origin and he refers to the fact that it was first 
observed in England in 1787 on some stock imported from 
* The classification of the Aiihidida? is at present in an unsettled state. 
Passerini (1863), in his ‘ Aphididse Italica',’ includes Schizoneura under 
the sub-family Pemiihigina'. Buckton (1875-82) separates the Peni- 
pliigina and Schizoneurina) as two distinct groups. Del Guercio 
(1900) classifies the genus Schizoneura in the gi-oup Myzoxylides, a 
division of the sub-family Myzo.xylina. Mordwilko (1908), classifies tlie 
genus Schizoneura (Hartig, 1841), in tlie grouii Schizoneurina, a division 
of the sub-family Pemphigina. Tullgi-en (1909), has adopted this 
position for the genus in his^ Aphidologische Studien.’ 
