352 



I 

 and the author's large reprint has just reached us. While we are not 

 deeply versed in the subject of insect embryology, this work strikes us 

 as a very able production. It covers 148 pages and is illustrated by ' 

 .six large folding i)lates. The subjects treated are: The embryonic de- 

 velopment of the Locustidie; Gastrulation m the Orthoptera; the in- j 

 dusium and its homologues in the Arthropoda; General considerations'''^ 

 of the embryonic envelopes and revolution of the insect embryo ; JSTeuro- . 

 genesis in the Insecta; the development of the reproductive organs in j 

 the Insecta; the subcesophageal body in Xiphidium and Blatta; Tech-r-| 

 nique; Bibliography. The species among the Locustidte to which he 

 has devoted his principal attention are Xiphidium ensiferum and Or- 

 chelimum vulgare, ai^d certain biologic facts of interest concerning each 

 species are placed on record incidentally to the main purpose of the 

 work. He has made the Orthoptera a starting point in his studies, with 

 a view of determining their relations to the Apterygota on the one hand 

 and to the higher orders on the other; for, although the primitive and- 

 synthetic character of the Orthoptera has been recognized by com- 

 parative anatomists, the full importance of the group, according to Dr. 

 Wheeler, has been but little appreciated from the embryological stand- 

 point. 



INSECTS SAID TO FORECAST THE WEATHER. 



In reply to our suggestion on page 138 of the current volume our val- 

 ued correspondent, Mrs. M. E. Rice, of Coryville, Pa., sends us the fol- 

 lowing local ideas concerning insects and the Aveather: 



It is a common superstition here that the blaclc markings on the Ia7-vw of Fyrrharc- 

 tia isabeJla, or " Wooly Bear" as it is commonly called, foretell the severity of the 

 weather during the winter. If the black is longest on the head end the forepart of 

 winter will be severest, and if rice verso, then spring will be coldest. Now some of 

 the larva; are black at both ends, some either one or the other end, while some are not ' 

 black at all, or faintly marked. Whether this variation is owing to sex or food or envi 

 ronment I know not. A continuous flight of Dragon flies is said to portend a wet 

 spell (I should say follow a dry spell). Observation shows that a sudden inroad of 

 flies is a portent of rain. Spiders lie dormant in winter; before a thaw they liven 

 up. An irrujition of black ants in my house when the thermometor has for weeks 

 hovered below zero, means to my mind an open spring. Such an one occurred last 

 20th of February and caused nie to prophesy mild weather. I was derided, as we 

 generally have "six weeks winter lu March" here, but events proved that I was 

 correct. Snails (spiral snails) crawl about only on the approach of wet or cloudy 

 weather. You may expect rain in six hours from their appearance. 



WHAT CONSTITUTES A SPECIES. 



One of our correspondents who is just beginning the study of system- 

 atic entomology has recently written us inquiring what constitutes a 

 species. To this inquiry we have made the following answer : 



Your qiaestion regarding what constitutes a species is a broad one and not easy to 

 answer in brief. In the abstract, a species is limited by the capacity of its individ- 

 uals of both sexes to couple and produce fertile olfspring, and to continue this indefi- 



