1897] ENTOMOLOGICAL NEWS. 39 



Dr. Geo. H. Horn has been seriously ill, but we are glad to state lie is 

 tiiiich better and out of danger. 



Dragonflies in hot water. — In "The Museum" (a natural science 

 journal published at Albion, N. Y.) for October, 1896, Prof. M. J. Elrod 

 gives some of his experiences in the Yellowstone National Park, as the 

 sixth installment of a series entitled, " Among the Rockies." After de- 

 scribing the Fountain, Excelsior Geyser, Turquoise and Prismatic Lakes, 

 he says: "We had observed in the lakes and in the outlet to the crater 

 [of Excelsior Geyser] numerous dead dragonflies. They had met a sad 

 fate and had come to an untimely end by too close proximity to these hot 

 steam vents. Now these were what we were after, though we had as yet 

 taken none in the Park. There is no law against catching insects or dig- 

 ging plants, so we prepared for action. We soon struck a warm stream 

 along which hundreds of beautiful large red-winged Libellula sattirata were 

 sporting themselves, and mixed among them were many smaller blue- 

 colored JMesothemis simplicicollis var. collocata. All the boys took a 

 turn, and tliat ravine was well swept. The insects were frequently seen 

 depositing eggs in water that was hot to the touch." Then follows a de- 

 scription of L. sattirata. "The next most noticeable dragonfly to L. 

 saturata is Mesothemis shnplicicoIHs var. collocata Hagen [«o/Say]. It 

 was found in the Park quite abundantly, generally with L. saturata. On 

 account of their staying in close proximity to small warm pools and run- 

 ning streams they are not difficult to catch. One could generally straddle 

 the stream and sweep from either side as they went past, or secure a 

 favorable position near a pool and sweep them, while a second party 

 would^ keep them on the wing. They fly low in the Park, do not take 

 long flights, and by their bright blue bodies are quite conspicuous, though 

 not as much so as L. saturata. Quite a number were captured by 

 throwing hats over them, though by such means failures were the rules 

 and captures the exception. Hundreds of these were seen in various 

 pools where the water was too hot for the insects. In some cases they 

 were cooked, and were so soft and unsightly as to be useless as speci- 

 mens. At first it would appear difficult to account for thtir presence in 

 these hot pools. From the fact that many males are among the dead it 

 cannot be from an attempt at depositing eggs in water too hot to endure. 

 They undjubtedly are overcome by the escaping steam, smothered and 

 boiled." 



The gizz.vrd of dragonflies (odonata). — Dr. F. Ris, of Mendrir.io, 

 Tessin, Switzerland, in an article entitled, " Untersuchung iiber die Ge- 

 stalt des Kaumagens bei den Libellen und ihren Larven" ( Zoologischer 

 Jahrbiicher, ix. Jena, 1896) describes the gizzard of these insects as the 

 terminal portion of the foregut, whose ectodermal cuticle is variously 

 thickened and armed with microscopic teeth arranged in rows or on alter- 

 nating areas. The presence of such structures in insects so well provided 

 with cutting and biting mouth-parts is explained as necessary, owing to 



