412 C. H. TURNER 



Patch (74) contends that the most important problem in the 

 ecology of any aphid is, " Does it migrate ?" 



In his investigations of aquatic Lepidoptera Welch (116) 

 studied both Nymphala macularis Clem, and Nymphala iccualis 

 Wlk. ; but, most of his time was devoted to the former. The 

 larva cannot swim; its sole method of locomotion is by crawling. 

 In both species case-making is a constant larval activity. The 

 case is constructed out of bits of the leaves of the food-plants. 

 This case serves as a protection and as a float. 



LETISIMULATION 



It is well known that the coccinellid beetle Epilachna borealis, 

 when disturbed, folds its antennae and legs against the body, 

 ejects small drops of liquid from its femoral articulations and 

 feigns death. What is the nature of this excretion and how is 

 it expelled so quickly ? Mclndoo (64) has demonstrated that 

 this " reflex bleeding " is a true reflex, that the fluid is secreted 

 by hyperdermal glands, that it is ejected through groups of 

 pores situated on and adjacent to the articular membrane, and 

 that its ejection is accomplished by putting the gland cells 

 under high blood pressure. 



DuPorte's (27) description of the death-feigning of Ty chius 

 picirostris harmonizes with the accounts of the letisimulations 

 of other invertebrates as related by several recent investigators. 

 (1) There is much individuality. (2) There is no relation between 

 the intensity of the shock and the duration of the feint. (3) It 

 is impossible to prolong the feint indefinitely by means of re- 

 peated stimulations. (4) The animal may be much mutilated 

 without being aroused from the feint. He thinks that the physico- 

 chemical reaction responsible for the manifestation of the death 

 feint is of the same nature as that which calls forth the thig- 

 motactic responses of many insects and other animals and such 

 plants as Mimosa. The reaction is segmental and not controlled 

 by the supra-oesophageal ganglion. 



MIGRATIONS 

 Osburn (69) has a short note on the migration of dragon- 

 flies and Barber (7), one on the migration of Myrapods. 



About five years ago, Zetek* devised a method of marking 



* Determination of the Flight of Mosquitoes. Ann. Antom. Soc. of Amer., 1912, 

 vol. VI, pp. 5-21. 



