ENTOMOLOGIST AND BOTANIST. 



231 



by a very short interval ; near the tip of the ab- 

 (loiiien tliere is a row of still more niiuute spines. 



I (lid not see the exclusion of the perfect in- 

 sect ; but, according to Verdat, after 13— li days 

 spent in the pupa state, the thorax splits and the 

 fly escapes, wrapped in an air-ball, which makes 

 it rise rapidly to the surface of the water ; during- 

 this interval, the limbs remain folded as in the 

 pupa ; but as soon as it reaches the surface, the 

 limbs unfold themselves in an instant and the 

 fly walks on the water towards the next stalls, 

 where it remains until its wings have become 

 sufliciently hardened. 



The imago of S. reptans has acquired in Eu- 

 rope, under the name of "the gnat of Colnmbatz," 

 a reinitation equal to that of Glosdna morsitans, 

 the African Tzetze. Immense clouds of this 

 bloodthirsty gnat infest the banks of the Danube 

 on the Hungarian as well as on the Servian side, 

 where the castle of the Columbatz is situated. 

 Their numbers are such that animals attacked 

 by them seldom escape death, as they not only 

 cover the skin, but penetrate in every orifice, 

 even the lungs, and produce the most intolerable 

 inflammation. More than six himdred head of 

 cattle were destroyed in that region in the single 

 year of 1783. The same gnats are mentioned in 

 Poland as far back as 1670, where, according to 

 the (probabh- exaggerated) accounts of the time, 

 thirty men were killed by them. In the Northern 

 States and Canada, Simulium is known under 

 the name of Black-fly, and is, in some regions, 

 very annoying. In the West, it is called Buffalo 

 gnat, and I have heard of a case of destruction, 

 caused by them to mules at Vicksburg. which 

 fully equals that of Columbatz. 

 AUTHORITIES. 



ElcnnORN — XaturqeKh. d. Kleiiistm WasserlhUre. 

 Danzig, liT4. Tub. VII. Contains, according to a 

 statement In Thon's .Vrchiv, Vol. II, a rough figiu'c of 

 the larva. 

 i ■ Otto FAHi;icirs— Sclirirt. (I <^p—l|.r!,. ,1 imturf. 

 Fremiilc in lln-lin. \"cil. \' . [> -'.'i -I'^'k i --i.i Tlie 

 article i~ mtitlcil • ■ l'.rMiiiiiliiiii_ \ \ - i!,i.!>r unci 



Hirer riqilir.' ' :ill-l r,,||l;;i||. h ),.■:_ , ,, ,, !i|, pupa, 



its pouril, auM ..I' !ii,' iirrli-.-t iii-> , I . Ili, \:,r\:, was not 

 known to Fabricius-. 



Veudat— Mem. pour servir ii I'bistoirc dcs Simulks, 

 prcscutc 11 la SocTI'liist. natur. Ue Bale en 1821. In 

 Naturw. Anz. tier .Sebwrizci-. Ciiscllscli ; 1S2:!, Vol. V, 

 p.U5, tninshitcd in German m I h-n'- AivI.k. 1 1 , 2, pp. 



ee-eii, will, li-un- t;, ■ , i ..nth,' 



: subjecl ; tin- li-un- ai- ■ . ,i..luced 



on areiUi.-c.l --.al.' ii, \V , ii ;:, i..., l:i, 20. 



Althonuh \, i>! a . „ - , («,«,. 



r«p;««.,;[an,in.i:.^..v :„. :, ,,, ,: :. . ,. ,.■' 



, Friks-JA., . :r j.,^- : \, ..l.anica: 



"Obs,a-vati..,i. i _:., ■ . r,,^ 1, a_. .. : il.p.), 



Vl^xticmm—IIlstou-e d 

 Simulium: Montpellier, 1844. Reproduction of already 

 known facts, with some new details, and especially some 



1 1 1 nitom\ of the lai\a. No platen S 



lltdung de<s ion Di Medcnicz an die 



er^faiUfen Benehtet uh die Eniste- 



I 1 Col }1ite>Mulr (Sitzune*, 



I I 1^4^ w til till I lite-) Medo- 



1 1 I 1 i' II 1 t ■- ? m Kolhi 



1 1 ut i1ri\m i\ > n >thingne\\ , 



I I il 11 ol thi lai\ I, which ]>> diawn on i 



III 1 nitiire The tigiue of the pupa is bor- 



I ] 111 Fo-M - i);;/t/ ( i(«i!nactt,p 14(1848) 



' 1 1 1 I nothing new 



111 II lc,1848,p 204(with 

 I I 1 iiRi luthois, ligiues 



1 III 1 -1 lie 



jvii I iKti — oli-m itiuiiLs di puma in-ectorum ijen- 

 CM luiiu, 1842 Di-oeit luiu^. Embryological re- 

 st irchc-i on the de\ elopment of the Hi \ \ in the 

 (^ canfsfCT', Bremi, n sp ) 



:hc eg^ 



BL.VCK KNOT. 



It was long ago shown in the Practical Ento- 

 mologist by Mr. Walsh, that the Fungoid dis- 

 ease known under the name of " Black Knot" 

 to infest the cultivated Cherry ,was quite distinct 

 from the disease of the same name which attacks 

 the cultivated Plum ; and that the former most 

 probably took its origin from the wild Choke 

 Cherry {Cerasus virgiaiana), and the latter 

 from the common wild Plum (Primus ameri- 

 cana). Hence there followed the important 

 practical consequence, that Black Knot could 

 not spread from Cherry on to Plum or from 

 Plum ou to Cherry ; each parasitic fungus con- 

 fining itself to its appropriate tree. 



In July, 1800, we were favored by Mr. B. 

 N. McKinstry, nurseryman, of East Sumner, 

 Kankakee county, Illinois, with specimens of 

 Black Knot growing (piitc abundantly with 

 him, as he says, upon the Miner Plum, but 

 not on any other cultivated plum. A single 

 glance suffices to show that this diseased growth 

 is essentially distinct from the common Black 

 Knot of the Plum, although like this last it is 

 evidently of fungoid origin. In fact, both in 

 color, ill external texture, and in internal or- 

 ganization the two ditfer so widely, that "Brown 

 Knot" would be afar more appropriate name 

 than "Black Knot" for the afTectioii of the 

 Miner Plum. 



As the Miner Plum is a cultivated variety of 

 the Chickasaw Plum (Pruiius chicasa), it would 

 seem to follow that there are three distinct 

 Black Knots, originating respectively from 

 Choke Cherry, from the common Wild Plum 

 and from the Chickasaw Plum ; and further, that 

 the first is confined among our cultivated fruits 

 to Cherry, the second to our common tame 

 plums, and the third to the Miner Plum. It is 

 very remarkable that in Europe they have no 

 Black Knot at all, whether upon Cherry or Plum. 



