SCIENTIFIC NOTES. 167 



sesmentai membrane is represented only by a little thickening of the integument 

 at the incision. At C.C., B.B. however, where the maxillae lie in front of the 

 membrane, such contraction is modified. B.B. reaches C.C, but the anterior half 

 of the intersegmental membranes remains behind the maxillee and the posterior half 

 comes in front of them, so as to form the pocket. 



SCIENTIFIC NOTES AND OBSERVATIONS. 



Attacks on insects and allied questions. — There are several 

 active collectors in this vicinity and we are all interested in "Mimicry" 

 and the various lines of thought which go with it. It is surprising 

 what important things may be and are passed by trained students of 

 nature if they are not in line with the work undertaken. For example, 

 this matter of iinperfect specimens of butterflies taken in a day's catch; 

 I suppose about one collector in a hundred would stop to consider the 

 nature of the damage. This season I am preserving and counting all 

 the damaged specimens, and up-to-date find that nearly 8% show un- 

 mistakeable signs of encounters with their enemies. Last Sunday I 

 took notice of an occurrence which I have probably seen dozens of 

 times but made no mental note of it. A large, active, grey lizard 

 (very common in California), about eight inches long, ran briskly over 

 the surface of a thickly flowering wild lilac bush and snapped up flies, 

 bees and other insects with the greatest ease. I've seen thousands of 

 lizards running around on the ground and over the rocks, but never 

 imagined that one could travel so freely and easily over a flowering 

 bush even though it was ver}^ dense. I have no doubt that most of 

 the torn wings on butterflies in this vicinity are caused by these lizards 

 and am planning to carry on some experiments on this line. 



Another interesting line of thought which has attracted my 

 attention lately is connected with the chrysalis stage of butterflies. 

 The most interesting species I have studied so far is Papilio zolicaon. 

 1 have several hundred chrysalids under observation. Some are nearly 

 two years old and still healthy with only occasional deaths. I shall 

 keep accurate records of larva, chrysalis and imago dates together with 

 sex data for three more years, making a total of five, and then tabulate 

 and try to draw some conclusions. When I tell you that thq first lot 

 of about thirty chrysald dates in November and December, 1912, have 

 imago dates running from three days to the present time, and with 

 half-a-dozen still in the chrysalis state, you may imagine what lines 

 of thought open up. This southern county is serai-arid and frequently 

 we have several years with very little rainfall. The food-plant is fitful, 

 sprouting after the irregular rains. If the imagines all came out at 

 some certain season, they Avould very likely have no food-plant upon 

 which to deposit eggs. The protective colouring and evil smell of the 

 larvse aid to preserve the species, while the irregularity of butterfly 

 season and the apparent chances of failing to mate counteract this. 

 In fact I find that a long continued observation of simply one species 

 brings out all kinds of ideas. 



I hope to see some more work done on the bird versus butterfly 

 question from now on, and will send you copies of anything that may 

 be published locallv. - — J. R. Haskin, Los Angeles, California. 

 May Uth. 



