F. H. Stewart 
173 
In specimens sent to me in January I found adult and larval A. fragariae, 
in large numbers as ectoparasites under the scales of the bud. In serial sections 
(Fig. 32), they are seen lying among the hairs on the surface of the growing 
point. 
The definitive habitat of A. olesistus and jiJiyllophagus , that in which 
feeding and reproduction proceed most actively, and in which their pathologi¬ 
cal effects are manifest, is in the mesophyll spaces of leaves; they are never 
i-1-1-1-1-> 
Fig. 31. Chrysantnemum leaf, transverse section through a stoma, showing A. phyllophagus 
in a mesophyll space. 
Fig. 32. Strawberry plant, transverse section through the bud, showing A. fragariae on the 
surface. 
intracellular, and avoid tissues without spaces (Ritzema Bos, 1893; Molz, 
1909); they occur frequently close to the stomata. 
Migration in the tissues of the leaf. Ritzema Bos (1893) believes 
that A. olesistus travels in or along the outside of the nerves. Molz (1909) 
denies this, and asserts that migration only occurs through the spaces of 
spongy tissue, and on the surface; he finds the vessels of chrysanthemum 
leaves to be too narrow to admit the parasite; the animal wanders out of the 
