148 ENTOMOLOGICAL NEWS [April, 'l2 



Frequently the posterior part of the cast skin is left attached 

 to the anterior part, and is not torn entirely apart from it, as it 

 was in the case of the individual which was observed molting 

 under the microscope. 



Although I never have observed the second and third molt- 

 ing processes, a study of the second and third cast skins would 

 indicate that it is essentially the same as the first one. 



The Four Stages oe the Molting Process. 



From the observations made of the molting process it may 

 be divided into four stages. 



The first stage (Fig. i). This stage begins with the first 

 movements of the body, and ends with the complete transverse 

 rupture of the old integument. 



The second stage (Fig. 2). This stage begins with the 

 transverse rupture of the old integument, and ends with the 

 complete shedding of the anterior part of the old skin. 



The third stage (Fig. 3). Includes that part of the process 

 between the casting of the anterior part of the old skin, and 

 the complete freeing of the body from the posterior part of 

 the old skin. 



The fourth stage (Fig. 4). Includes that part of the process 

 coming after the last part of the old skin has been cast and 

 extending until the rest period due to exhaustion sets in. 



A Part of the Chronology of the Molting Process as Recorded. 



Ames, Iowa, December nth, 1909. 



Time : Individual in cell A. 25. 



A.M. 



11.50 The first movements noticed in the quiescent larva. These 

 movements were back and forth and sideways, with the legs 

 fixed at their tips by means of the tarsal claws. 



11.54 Last part of the old larval skin is detached from the body. 



12.00 The new nymph stops "trying out" its new pair of legs, the 

 hindmost pair; and stretches itself out motionless and pre- 

 sumably exhausted. 



P. M. 



12.12 Period of rest is broken by the "trying out" of the new and 

 old legs, but not bv walking upon them. 



12.15 Nymph begins walking about although its gait is not steady. 



12.17 Observations stopped. 



