4l6 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Skr. 



potted branches in the laboratory all left the branches and 

 disappeared in a few days. 



June I, 1900, I marked several females on a redwood tree 

 at Cedro Cottage Place, which were just beginning to secrete 

 ovisac. I watched them until the young had disappeared 

 from the egg-sac, and although I searched very carefully 

 for these young on leaves and branches none was found. 



In January, 1901, I found the young insects abundant on 

 this same tree and of exactly the same form as the just 

 hatched larva, the antennas still being six-jointed and of the 

 same formula, legs the same shape. The only change that 

 had taken place was that they had grown to nearly twice the 

 size of the very young stage. They must, therefore, con- 

 ceal themselves on the branches or in the bracts at the base 

 of the leaves on the lower branches, where they are thick 

 and protected. There they lead a semiquiescent life for a 

 period of about six months. In the first days of January 

 they began to crawl about and were easily found, always, 

 however, partially concealed at the base of the needles. 



2. Second Larval Stage. — These larvae grew quite 

 rapidly, and about February i the antennae became seven- 

 jointed. There was, however, no perceptible change in 

 form at this time. Possibly a third change maybe noticed 

 in the male just before pupation, but it is very slight. In 

 the course 01 these three stages I have not actually observed 

 any moulting. 



3. The Male Pupa. — The male begins to secrete the 

 wax for its cocoon about February 20, and I have found 

 the completed cocoons by March i. Now begins the radical 

 transformation of the male larva, a complete metamorphosis 

 being undergone before the fly issues. The whole process 

 occupies a period of about twenty days. 



The process of emerging from the pupal case and skin is 

 very interesting. On March 21, at nine a. m., I found the 

 young male in the cocoon which was completed March i to 

 be in the act of emerging. The pupal skin first split along 

 the dorso-median line of the head. The head suddenly 

 burst through, next the wings, then the legs. In the process, 



