+ 
AND MORPHOLOGY OF APHIS. 235 
consequence of the enlargement of the pseudovum (9), which is about „45th of an inch in 
diameter. 
Fig. 3. The pseudovum is still more enlarged, and the second chamber is nearly distinct. The vesicle,’ 
e, remains, and exhibits certain indistinct granules in its contents. The cells of the blasto- 
derm of c measure about 3-,;th of an inch in diameter. 
Fig. 4. The second chamber is quite distinct from the first, and contains a mass (g) in which no clear 
vesicle could be discovered: this mass became clearer and irregularly areolate by the action of 
water. 
Fig. 5. The cellular germ-mass. The cells or clear cavities have a diameter of about 33 sth of an inch ; 
their endoplasts are hardly more than :5455th of an inch in diameter. 
Tas. XXXVII. 
Aphis Pelargonii. Letters as before. 
Fig. 1. A portion of the blastoderm and pseudovitellus of an unaltered germ, only ;i.th of an inch in 
length, but otherwise like the preceding. The clear vesicles measured „„;sth of an inch; the 
endoplasts r7åzsth. 
Fig.2. A germ extracted from its chamber and treated with acetic acid. It has no pseudovitelline 
membrane. 
Fig. 3a. A germ extracted from its chamber. It is enclosed within a pseudovitelline membrane (4); and 
its pseudovitellus is arranged in obscure spheroids, of which one is represented in 3 4. acted on 
by water. Its granules are about s¢;sth of an inch in diameter. 
Fig. 4. Germ gzl;th of an inch in length. The cells of the posterior end (3) present a sort of break (1), 
and the blastoderm on one side is greatly thickened. The thickened portion offers an indication 
of a division (m). "The anterior end (y) is also somewhat thickened. 
Fig. 5a. Germ „45th of an inch, enclosed within its pseudovitelline membrane: n. rudiment of the 
abdomen; o. of the thorax; p. of the head; /'. gap corresponding with Z, and now filled by the 
pseudovitellus; g. inner layer of the germ; 7. that portion of it which will become the pseud- 
ovarium. 50. Diagrammatic view of the same, viewed from above. 
Fig. 6. Lateral view of a larger germ without its pseudovitelline membrane. "The anterior part of the . 
cephalic blastoderm (p) has extended upwards, and constitutes the procephalic lobe p'. The 
rudiment of the pseudovarium (r) is still more distinct than in the preceding. 
Aphis Pelargonii. 
Fig. 1. Embryo enclosed within its pseudovitelline membrane. The pseudovitellus has aggregated over 
the abdomen, and more or less completely left the thorax. Letters as before, se the 
first larval integument; lb. labrum; at. antenna; 1v. mandible; V. first maxilla; vr. second 
maxilla; vir. first, viri. second, and 1x’. third thoracic leg. 14. The same embryo seen from 
below. ; ld d th 
Fig. 2. Embryo of the same size, viewed from below and the side, the blastoderm unfolded, an » 
appendages separated. : fih iem 
Fig. 3. Highly magnified view of part of the pseudovitellus, and of the rudiment of the pse : 
: in an embryo th of an inch in length. 
Fig. 4. Embryo «th of an inch, enclosed in its pseudovitelline membrane. 
Fig. 5. Embryo 74th of an inch, in its pseudovarian chamber. 
VOL. XXII. 
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