240 



Circulatory system. There is, as in all insects, a contractile 

 (pulsating) dorsal vessel, with venous ostia and arterial 

 branches ; but it was impossible for me, in the numerous speci- 

 mens received in a dampish condition, to find the dorsal vessel 

 or its ramifications, w' hich would have been easily done in living 

 individuals. 



Mespiratory system. Ambljchila has seven pairs of stigmata 

 (nine in the larva). The tracheae present a diversified system 

 of ramifications, with the occasional occurrence of dispersed 

 tracheal expansions, or bulbs, in the smaller branchlets, as is 

 the case in other insects. Correspondences occur between the 

 tracheal system and many of the other organs (corpus adiposum, 

 integument and muscles), whereby an aeration of the blood is 

 not only possible in all parts of the body but also in the respect- 

 ive tissues themselves. 



The respiratory system assists locomotion by considerably 

 lessening the specific gravity of the body. 



Muscular i^ystem. But little can be said about the muscular 

 system of Amblychila, though a few general remarks may be 

 useful and instructive. As in all arthropcda the muscles are 

 individualized, consisting of a number of single fascicles of 

 fibres. The wings are \vanting and the elytra connate, conse- 

 quently the muscles destined for the wings are rudimentary. 

 A number of leg-muscles are inserted on both sides of interior 

 prothoracic processes. Stout fascicles in the head move the 

 oral organs of this carnivorous insect. Several ligaments and 

 membranes connect the head with the thorax, and the latter 

 with the abdomen. The pharyngeal muscles have been men- 

 tioned before. 



As is the case in all arthropoda the muscular fibres are trans- 

 versely striate. Since I received only dead specimens, I could 

 find only striate muscular fibres ; striate fibres also occur in 

 living insects, however, as Franz Leydig and August VVeismann 

 showed in the larva of Corethra. 



Nervous system. (Fig. 1.) I succeeded in tracing the ner- 

 vous system in several individuals. Having macerated the 

 bodies in water several days, I opened them from above, at the 

 sides, and having carefully removed corinis adiposum, digestive 



