30 ANATOMY OF THE SUGAR LOUSE. 



The external reproductive organs in the female sugar-louse are placed 

 under the middle long bristle of the tail, in form of a plate, or rather 

 of a longish pipe (P, fig. 1), lying between two plates (Z) of a horny 

 structure, running to a point, and having on the sides six small jointed 

 bristles (q, m, ri). At first sight, this has so much resemblance to the 

 external reproductive organs in the male of the common wood-louse, 

 that we may readily mistake this female for a male, and thus find 

 another similarity between the two species for which there is no 

 grounds. On more close investigation, it is found that the organ in 

 question is cleft, and is in reality an ovipositor (leyestackel). This ter- 

 minates above in a short canal, at the upper end of which are two small 

 bladders (T, rf), and a knotted egg-organ (E, E, fig. 2). The bladders 

 I met with only in the full grown insects ; and in such individuals as I 

 found them, the egg-organs were absorbed (ausyeleert), and no longer 

 apparent. I was therefore obliged to represent these parts in two 

 separate figures. The bladders are oval, and separated by a contrac- 

 tion into two parts. From each of the two egg-organs there runs a 

 single tube (E, d, E) slightly curved, which is furnished on the outer 

 side with five short branches containing eggs (E). , 



The external reproductive organs in the male are precisely in the 

 same situation as the ovipositor in the female, exactly between the two 

 horn-like plates, which, however, are in the male smaller than in the 

 female, and somewhat different in form. The external part (ruthe) is 

 very short and cylindrical, with two lips wherein are two gut-like 

 organs, rather wide, and two longish tubes (a, b, c, fig. 3). These two 

 organs are curved and ringed. The two tubes are narrower than the 

 former. These become wider as they ascend, and stand farther apart, 

 afterwards curving downwards, in forrn of a slender film, which again 

 runs upwards and outwards, ending in several minute branching, 

 longish, bladders. 



12 11 10 9 8 



Fig. 1. 



ftUWUUl g _ . ^ ^ 



Fig. 2. 



I have been long in doubt respecting the organ of breathing in the 

 sugar-louse, and have not yet arrived at any certain conclusion. I 

 imagined, at first, that I could distinguish the air tubes (trachea:) ; 



