MORPHOLOGY OF THE LEPIDOPTEEA. 159 



attached extremity of a right larval oviduct is figured PL XVI. fig. 32. The left oviduct 

 of the same specimen had an exactly similar appearance, and hoth end in a single 

 root. A delicate and short filament passes from the oviduct near its root to the hypo- 

 dermis. It seems to consist simply of nucleated connective tissue, and in that case 

 would point to the existence of a superficial coat of cells such as was found by Spichardt 

 to invest the pupal vas deferens of Liparis dispar. He states that the coat was absent, 

 however, in the pupas of Smerinthus ocellatus and of other species examined by him, 

 though it appears to be always present in the adult. See Verhandl. des naturh. 

 Vereins der preuss. Eheinlaude, 1S86, pp. 7, 8, 28, 29. A small trachea also approaches 

 the root of the oviduct, but I do not know its destination. Bessels, in the Zeitschrif t 

 fur wiss. Zool. xvii. 1867, describes (p. 561) the oviduct as terminating in tbe hypo- 

 dermis (Schleimnetz) by four unequal branches each of which " opens " separately ; and 

 lie makes this mode of termination distinctive of the oviduct as contrasted with the vas 

 deferens, which " opens " by a single slightly broadened out termination. He figures 

 (Taf. xxxiv. fig. 30) the ventral end of the oviduct of Gastropacha rubi. The oviducts 

 are at this period, as at a later, solid structures (PL XIX. fig. 59) *. 



The ventral muscle-bundles leave a small space in the median ventral line uncovered 

 throughout the whole length of the abdomen. The chain of nerve-ganglia overlies this 

 space. The terminal and compound ganglion of the chain is situated about its centre in 

 the seventh somite and forms a very convenient landmark. In the vacant space of the 

 eighth somite, and in its posterior half, is a rounded body divided by a median furrow 

 into two oval halves, one right, the other left, rarely completely symmetrical and alike. 

 A second body is placed in the vacant space of the ninth somite, but in its anterior half; 



* The male caterpillar may be at once identified by the following points of structure : — The testes are placed 

 close together dorsally in the same somite as are the ovaries, but each of them is a deep orange-coloured semilunar 

 body divided by three furrows into four segments one behind the other. The convex aspects of the testes are turned 

 towards one another. The rudiments of the four future testicular tubes are placed transversely. The vas deferens 

 originates from the concave aspect of the testis and from its third segment. It passes behind the eighth abdominal 

 spiracle, and then turns round the bundle of tracheae originating from that spiracle towards the ventral line, but 

 above, not under, the musculature. The two vasa deferentia are attached to the anterior edge of a small disc-like 

 body, which in its turn is attached by filaments to the ventral surface of the rectum, and not to the hypodcrmis as 

 Herold states of Pit ris brassicce. The invagination of hypodermis destined to form the ductus ejaeulatorius and 

 accessory glands takes place in the ninth somite, and in the position occupied by the paired posterior vesicles of the 

 female (PL XVII. fig. 33). 



The testes and ovaries are often dissimilar in colour. Bessels gives the following table (Zeitschrift fiir wiss. Zool. 

 xvii. p. 553) : — 



Species. Ovary. Testis. Fat-body. 



Liparis dispar Yellow. Flesh-red. White. 



Gastropacha potatoria „ Yellow. „ 



SpJiinx euphorbia „ Eeddish. Yellow. 



Pontia brassicce „ Violet. White. 



Cossus ligniperda White. White. „ 



Sphinx ligustri and Phalera bucephala agree, I find, with Cossus. In Pontia ( = Picris) brassicce the fresh fat-body 

 posteriorly to the 6th segment is greenish or olive-yellow, anteriorly to it opaque yellow or green on the dorsal 

 aspect, but on the ventral aspect white. The fat-body of Vanessa Io is yellow and becomes orange in the pupa. 



SECOND SERIES. — ZOOLOGY, VOL. V. 25 



