Pomona Com.ecje JofRNAL ok Kntomoixxiy 859 



OUSKHVATIONS ON TlIK KCOLOOY OF I)KA<iON-FLY NY.MI'IIS: 

 HHACTIONS TO I.KillT AN'I) CONTACT 



C. K. Rll.KY 



Ann. Kilt. S.ie. Am. Vol. V, No. :j, 1!M2. 



In thi'ir natural lialiitat tlu'V n-spond stpongly to contm-t. Tlicy rcsponii 

 ni'iratively to stronj; lij;lit : this is a photic response and not a reartion to tem- 

 perature. They also exhihit a "elaspinj; response." sei/ini; eaeh other around 

 the thura.x and alidomen Ity means of their thoraeie appendages. Sometimes 

 as many as fifty individuals are ela-spetl toj;<'ther in this way. The respon.s*' 

 of these nymphs to photic stimuli may he overcome hy response contact. It 

 seems to tlie writer that the l)ehavior of the nymphs with respect to litfht and 



contact nuiy not 1 ntircly of a reflex mechanical nature. Such movenieiitM 



are not always precise and definite; .sometimes they are considerahly nuMlilied. 

 May they not. as Homes has shown with respect to i'anatra, pos.sess sonu' of 

 the <'oncomitants of the pleasure pain-reaction? The two .sort.s of n-spon.ses 

 seem to be heneticial to the nymphs. Such responses not only aid in conceal- 

 ment from enemies, but al.so a.ssist in obtaining f<K)il. Beneficial reactions are 

 fre(|uently '" plcasureable. " at least they are not usually "painful." On the 

 other hand injurious respon.ses are often "painfid." certainly not ''plea.sant." 

 The nymphs are Kuided fairly well by their "likes" and "dislikes," if such 

 terms may he used. 



THK NORTH AMERICAN DRAtJONFLIKS OF THE (JKNIS .KSTHNA 

 I'niversity of Toronto Studies Biological Series 



K. M. WALKER 



The first part of this work is taken up with a <letailed account of the 

 trenus Aesthna, beinfr mainly a study of the general life historj". Then 

 follows a key to the North American species, for both males and females, as 

 well as the known nymphs. Thorou^rh descriptions of the sixteen spe<Mes are 

 given. There are twenty-eight j)lntes, inchiding six colored plates of the 

 adults. 



Mabel (Uernsey. 



IBKR VKRSONDRISKN BFI LFl'IDOl'TKRKN 



DR. PAUL SCHULZE 



Zoologischer Anzeiger. April 30, 1912. 

 The moulting fluid glands, which have never before been notice<l in the 

 adult, were discovered in an adult Spilosoina lutnnn. The.se are apparently 

 the source of a secretion — probably protective — which lia.s been observed on 



the prothorax of certain Lcpitloptcra. 



Mabel Guernsey. 



