1921] WELLS—ZOOCECIDIA 365 
roll condition (7) and the variable pouch type (2). This latter in 
turn has given origin to such a kataplasma as shown in (3); which 
represents the work of many individuals, and the prosoplasma (5), 
which represents the work of but one insect, the stem mother. 
From the former has been derived such a spine-bearing prosoplasma 
as outlined in (4), from the latter the walled forms, the “umwal- 
lungen Gallen” of KitisTer (6), have had their origin. In these no 
diverticulum structure whatever appears, but the larva is walled 
in by a vertical upgrowth from the blade. Once this type of gall 
is attained, the insect is able to use the more rigid parts of the 
plant, namely, petioles and stems of the season, as a basis for 
gall formation. None of the aphid prosoplasmas have reached 
the level at which a sclerenchyma layer is differentiated in them. 
CoccipaE (Hemiptera) (pl. XXI).—Three fundamental primi- 
tive kataplasmas can be distinguished in the Coccidae forms, the 
simple umbo on the stem (1), the shallow leaf pocket (5), and 
the saucer-shaped incept of the up-walled type. From the latter 
‘have arisen those remarkable Australian prosoplasmas character- 
ized by differentiation on the sex basis, that is, the male and 
female larvae produce differently shaped and constructed galls 
(4a, male; 4b, female). One of these (3) shows the development 
of appendages borne on radiating arms. Its form is more primi- 
tive than the gall of (4), and in the absence of anatomical data 
pertaining to any of these forms, it is tentatively given a lower 
position. I can only find the statement that the female galls are 
“woody”; the information as to whether or not specific scleren- 
chyma layers are differentiated has not been obtained. 
Mus1wae (Diptera) (pl. XXII).—Gathered together under this 
superfamily name are a number of related dipterous families which 
are represented by kataplasmas only. Three fundamental begin- 
ning stages can be distinguished, related to the plant part attacked: 
a simple rosette resulting from the abortion of the stem axis with 
concomitant abortion of leaf elements (1), a simple cortical swell- 
ing (2), and the hyperplasia of the floral disk in certain Compositae 
(4). As an advance on the second are those cases in which the 
larva goes deeper, taking a central position in the stem, giving the 
intercalate globular type (3). 
