ANATOMY OF THE SUGAR LOUSE. 



29 



from the mouth downwards, widening out as it descends to the breast into 

 a capacious reservoir, which is held to be the crop (B, C), succeeding 

 to which is a second cavity, smaller, and of a tapering form (C, D)» 

 The inner part of this is represented as laid open in figure 2. It is 

 furnished on the inside with six teeth, of which 2 and 6 have the same 

 interior structure as 3 and 5, differing in this from the upper ones L and 

 4. The two teeth 3 and 5 seem manifestly to seize, and the upper 

 teeth to bite and chew the food. It is not a little singular in an 

 animal which stands so low in the scale of organisation, to find such 

 an apparatus for manducation. There are similar stomach-teeth of 

 various structure, in the oriental cockroach (Blatta orientalis). This 

 gizzard or toothed stomach (zahnmagen) runs into a short, straight, 

 thin intestine (D, E, fig. 1), at the lower end of which four rather long 

 and very slender bile vessels (2) arise at a contraction of the tube. 



Ramdohr, in his work on the Digestion of Insects (Abhandlung, s« 

 1 50) , reckons the reservoir which I have called the crop or first stomach 

 as a part of the gullet, and imagines the part called by me the small 

 intestine to be a second stomach, a matter however which must be 

 arbitrary. My own opinion rests on the analogy of the wood-louse 

 and the centipede (Scolopendra). In the small tapering stomach, 

 Ramdohr has overlooked the teeth, and has incorrectly termed it a 

 third stomach (faltenmagen). Ramdohr is also wrong in representing 

 the sugar-louse to have only two bile vessels. 



The thick intestine is narrow at its origin, but becomes wider towards 

 its termination, enlarging very much under the middle long bristle of 

 the tail (E, G, fig. 1). Upon the back of the first and second stomach 

 there is an irregular mass of fat containing real oil. 



Fig. 1 Fig. 2. Fig. 3. 



