210 PROF. HUXLEY ON THE AGAMIC REPRODUCTION 



The granular pseudovitellus takes no part whatever in the formation of the reproductive 

 organs. In embryos of g'fth of an inch in length, I could very plainly observe a clear 

 space with an endoplast in the middle of each of its spheroidal masses (PI. XXXVIII. 

 fig. 3). Similar masses constitute a larger or smaller proportion of the corpus adi- 

 posum of the larva and adult insect ; and I believe that the latter proceeds from the 

 former. 



§ 5. Summary cmd Comparison of Germs and Ova. 



I will now sum up the results of the observations which have been detailed in the pre- 

 ceding pages. 



1. The pseudovarium consists of vagina, oviducts, and pseudovarian caeca. 



2. The vagina is unprovided with either spermatheca or colleterial glands. 



3. The pseudovarian cseca are each divided into many chambers by constrictions. 



4. The apical chamber contains bodies which are not distinguishable from the germinal 

 vesicles and spots of the true ovaria. 



5. These bodies, surrounded by a mass of clear substance representing a yelk, are set 

 free as pseudova, and are then imdistinguishable from true ova. 



6. The pseudova are eventually converted into cellular germs, apparently by the same 

 process as that by which an ovum is converted iato an embryo. 



7. In these germs the central part becomes a granular pseudovitellus, the peripheral 

 a blastoderm ; the rudiments of the different organs next appear, and the germ becomes 

 surrounded by a psevidovitelline membrane. 



8. Eventually the pseudovitellus probably becomes the corpus adiposum. 



9. All the other organs are developed from the blastoderm, which becomes distinguished 

 into two layers. Prom the outer of these the muscles, nerves, limbs, and tegument are 

 developed, while the inner gives rise to a part of the alimentary canal (?) and to the 

 reprodiictive organs or pseudovarium of the larva. 



10. The pseudovarium contains no particle of unchanged tissue of the germ, but is a 

 considerably differentiated and readily distinguishable mass. The mass divides into ten 

 lobes anteriorly ; and these lobes become the pseudovarian cseca. Before the larva is 

 ])orn, each caecum is divided into three chambers, the two posterior of which contain rudi- 

 mentary embryos. 



11. The genital apparatus of the oviparous female consists of a vagina, oviducts, and 

 ovarian cseca. The latter are multUocular ; and the vagina is provided with the sperma- 

 theca, and the two colleterial glands first demonstrated by Von Siebold. 



12. The rudiments of the ova are undistinguishable from those of the pseudova. They 

 are developed in the lower part of the apical ovarian chamber, the upper part of which is 

 occupied by the bodies I have termed ovarian glands. The ova are not at fii'st enveloped 

 in a chorion. 



13. In the lowest chamber the ova are provided Avith a chorion, vitelline membrane, and 

 what appears to be a micropyle. 



If these propositions are correct, I see no valid objection to the conclusion, that the 

 agamic offspring of Ajihis is developed fi-om a body of precisely the same character as that 



