14:8 Scientific Intelligence. 



in the formation of the existing species, which species Mo]iltliir\- 

 werc reofarded by Linniuus as uiichaiii^eable since tlieir first appiar- 



fortnas in hoc ^loho jtrodixit Inlinitiun 1mi>,"" etc., and so this axiom 

 holds its pUice'in the Ratio Operis of tlu' ^arne volume to which,at 

 the close, this hypothesis of the (liversiticatii)n of species is ap- 

 pended. I^ut we can hardly suppose that a ]>hilosnpher like 



ural causes, and then imagine that existent natural causes had 

 ceased to operate ; and he would certainly have seen that the con- 

 tinued crossing of the species of a genus would soon have resulted 

 in the total obscuration of species. If he thought at all of liamo- 

 nizing his practical definition with his suggested hypothoM?, lif 

 probably regarded S])ecies as havinir onlv a relative btability, so 

 as to be' essentially unchanged for any period within hutnan ken. 

 whatever their origin or ])rot;re?-s in tlie lonir run. 



To throw some light upon^Linn:eus's einnu-iation, which appears 

 so obscure, of an essential medulhirij snhsf'Oicr^ invested with an 

 accessory cortical suh'^tmice in :dl ])latits, Von .Mohl makes a long 

 extract from the dissertation of I.iiuueus upon (4encriitio Am- 

 bigena, published in the Gth vol. of the Ain.enitates Acadoinicffr 

 a curious speculation which would take some time to explain, one 

 to which Linnauis elsewhere refers, c-ptciallv in explaining the 

 nature of the blossom, and in uhicb d<.iil»tlcs-. a- Mold supposes, 

 is to be found the key to th- und. r^andin- of his derivative 

 hypothesis. A- *'■ 



13. Monograph of the R(w tin r,i!a.r , ,,fth< Don,)., ion of('"f«'^- 



r of th(■tri^r^1h(. pn.ili;,,. r.f tin- ^rrA i^ oinittt. 



diHicult for |.<,p„lar appn-lH-iiMon thoU'.!. it i 

 ough. PulsatJlla is kept as a genus,' but not Atr 

 ^o would seem to stand or fall together, and Ifejxff 

 Atremofie. Of the latter genus, the name J. 



■£'""''' 



admission of Thalictra 



Lawson shows that he has not foUowed up the history ui--- 

 species, nor noted that in the ^klanual its noithein limit ^-^^'J 

 be S. Virginia. lie should substitute the name T. n/""-^"'/'," ^^ 

 and see, for authoritv, PJ.,„ta. WrlahtUnor^ ii. p. N ^^''''/r;, 



r almost twenty ye 



Parry's collection. The first and la-t of tli 

 light also upon the notabji' pecnliurit \ rnei 

 leal distribution oi Ihlphinhon ,xalt'<itnn> 

 Canadian, is likely to inhabit only the mo 



