1915] 



Lyon — Notes on the Cat Flea 



129 



we were able to raise a generation, from egg to imago, in thirteen 

 days as the minimum to thirty-three days as the maximum, de- 

 pending upon the temperature. Moisture is essential for good 

 results. 



Table Showing Time of Development. 



In order that we might easily collect the adults on emerging, 

 the following device was used. After the larvae had pupated (in 

 pupating, the larvae may spin a thin cocoon or may pupate with- 

 out doing so, in either case the pupa stage is the same), the whole 

 culture was suspended in a glass funnel, deep enough down to 

 leave a clear space around the sides and not touching a glass plate 

 cover which was placed over the top of the funnel. The tube of 

 the funnel was inserted in a test tube and the entire apparatus 

 attached to a ring stand. The fleas on emerging from the pupa 

 jumped about and finally fell into the funnel and slid into the test 

 tube below, where they could be easily collected and handled (Plate 

 X). 



Observations on the Anatomy of the Larva. 



The statements and figures of the earlier authors, Laboulbene, 

 Kunckel and Taschenberg, are very indefinite but form the basis 

 of most of the later work. In the first larval stage, the head is 

 considerably longer than the other segments but in the last, third 

 stage, it is of the same size. The egg breaker is lost after the first 

 molt but the mouthparts remain the same. 



The broad convex upper lip or labrum of the mouth of the cat 

 flea is slightly emarginated in the middle with two small setse at 

 the center of either lobe (Fig. 1 C.) There are also two small hairs 

 on either side. The labrum is used extensively in locomotion and 

 in connection with the rest of the head to lift and turn over par- 

 ticles of food and in burrowing. In locomotion the two small setse 

 or bristles are fastened into the surface upon which the lava may 

 be, and act as a brace while the "caudal stjdets" at the extremity 



