THE AlilERICAN ENTOMOLOGIST. 



199 



of them from oft' the face of the earth ; but from 

 the rapid rate at which tlicy multiply tliere will 

 always be enough left for seed for another year. 

 It may be laid down, not only as a general, but 

 as a universal rule, that this insect is never 

 ruinously destructive, except in those sections 

 of country where there is continued hot dry 

 weather; and that if, in two adjoining districts, 

 there has been a dry summer in one and much 

 wet weather during the summer season in the 

 other, however plentiful and destructive the 

 bug may be in the lirst district, it will scarcely 

 be heard of in the second. Certainly this state 

 of facts is not exactly tlmt from which any rea- 

 sonable man would infer, that the paucity of 

 Chincli Bugs in a wet season is caused by an 

 Kpidemic Disease taking them oft". We might as 

 well maintain that, although there was no Epi- 

 demic Disease among the children of Israel that 

 had just crossed the Kcd Sea, or among the 

 Egyptians that staid at home, it was simply and 

 solely an Epidemic Disease (hat slew the pur- 

 suing hosts of the Egyptians and covered the 

 boltom of the Red Sea with their carcases. 



CABBAGE-WORMS UPON GILLY-FLOWEIIS. 



There i> a small green worm, alxmt one-tliird 

 of an inch long, which commonly infests cab- 

 bage leaves in the West, eating holes through 

 their substance, and when very numerous 

 riddling them like a sieve. When full-fed this 

 larva spins a very slight cocoon of white net- 

 work upon the cabbage-leaf, inside which it 

 transforms into the pupa, and subsequently into 

 the perfect moth state. The moth— which may 

 be recognized by the white hind margin of its 

 gray i'ront wings, aiid which scarcely measures 

 half an inch across its expanded wings— has 

 been imported into this country from Europe, 

 and according to Stainton, into all the four quar- 

 ters of the globe, wherever cabbages arc grown. 

 In this country, and probably in Europe also, 

 lliero arc two broods of them every year, one 

 coining out in the middle of the sunnner and 

 the other in October. (The proper name of this 

 insect is Plntella cruciferarum; but the late Dr. 

 Clemens, not being aware of its identity with 

 the European species, re-described it as Plntella 

 limbipenudla, and under the same circum- 

 stances Dr. Fitch gave it the name of Cerostoma 

 hntsskellu .) 



We have received specimens of this moth 

 from Capt. Edw. H. Beebe, of Galena, Ills., 

 along with some of its cocoons. lie says that 

 the larva is very destructive to giUy-flowers, and 



some other plants in green-houses, and that in 

 green-houses it hatches out into the moth state 

 as late as the end of November. This hatching 

 out as late as November, instead of in October, 

 is no doubt due, as Capt. Beebe suggests, to 

 artiticial warmth. The gilly-tiowers upon which 

 the insect occurred belong to the same botanical 

 family (Criicifenr) as Iho cabbage; and wc 

 loarn from its European name, that the larva 

 feeds in Europe u^ion a variety of species be- 

 longing to this great group of plants. 



PRACTU'AL IMPORTANCE OF SCIENCE. 



[•r™i,>l:.lia IVullI hv Sutm-.,U>U- IMliil.lini , .No. 1.] 



We lately met a friend who, lliinking that it 

 was necessary to apologize to us for not having 

 subscribed to our Journal, told us that he had 

 paid no attention whatever to Natural History. 

 " I care but very little," he added, " to know 

 whether a butterfly has a yellow tail or a red 

 one, and I willingly let that question alone 

 without troubling my head about il." "It is 

 fortunate,"' wc replied, " that there arc other 

 people who do not think as you do, for the thing 

 is- of more importance than you suppose. If all 

 the world had reasoned as you do, steam, elec- 

 tricity, magnetism, etc., would have never re- 

 ceived from man those practical applications 

 which astonish the intellect to-day, and consti- 

 tute the wonder of the age. A butterfly's tail 

 being yellow or red contains nothing which 

 ought intrinsically to interest us; but if by that 

 character one is enabled to distinguish a friend 

 from an enemy- a beneficial being from a dan- 

 gerous animal capable of causing considerable 

 damage — then this character acquires a very 

 special importance. And you ought to think 

 yourself fortunate,"' wc added, '• that others 

 have done for you what you do not feci the 

 courage to undertake for yourself, and have given 

 you the power, by means of such publications 

 as ours, to jump to results without having been 

 subjected to the toilsome labor of the demonstra- 

 tion — that is to say, to draw your interest with- 

 out having deposited any capital in the great 

 Bank of science."' 



The majority of our readers will, we think, be 

 of our opinion. They will proclaim Avitli us, 

 that progress among men demands the concur- 

 rent action of every intellectual power, and that 

 in working, each of us in the speciality which 

 has fixed our choice, we promote the general 

 good of the community, and engineer ett'ectively 

 for the grent cause <)f yeritablo progress. 



