P0ST-PL10CKNE CLIMATE IN CANADA. Jgi 
also some large specimens of the Emperor Mandarin Orange, which 
lso test, y to the excellence of the cultivation. It may be mentioned 
or the informat.on of those forming orangeries, that Mr. Oakes prepares 
'ns ground thoroughly. It is all well drained, and has been manured 
with bones and lime. 
POST-PLIOCENE CLIMATE IN CANADA. 
Principal Dawson has published in the ' Canadian Naturalist ' for 
ebruary, 1866, a list of some species of plants he has found in the 
well-known deposit of Leda clay, at Green's Creek, on the Ottoway, 
T 1 ; vhlch he has beei > able to arrive at a satisfactory estimate of the 
e nmate prevadmg there at the time of their deposit. ' The plants occur 
" he r er f rt of the Leda clay, which Dr. Dawson considers to be 
newer than the true Boulder clay. The species are :- 
"r*er* rotundifolia, L. Acer spicatum, Lamx. Potentilla cam- 
ThT Gayltmaccia resinosa, Tor. et Gr. Populm bahami/era, L. 
>tt«V T * ntallS > L - Potamogeioti perfoliatm, L. Potamogeton pu- 
, L. tyutsetum sclrpaides, Michx. And some undetermined species 
vancea Gramhea, and Alga, and a species of lontimlh. 
-one of the plants above mentioned is properly Arctic in its distri- 
'°n, and the assemblage may be characterized as a selection from 
hut 
the 
the T C ***AW fl ora of some of the more hardy species having 
most northern range. Green's Creek is in the central part of 
fo Pre'' Ta" t0 Ule Parallel ° f 46 ° ; aud an accidental selection from 
noddl i tll0U ' h [t U1Ight C ° ntaiu the Same SpecieS f0Und in the 
more eS ' Ik Certaiul - V i,,clude with th ™e, or instead of some of Hero, 
that t r S ° f ° nn3 ' M ° re es P eciaI1 y the Balsam Po P Iar > though 
Beat C !, ^ Ur8 P lentif ully on the Ottawa, would not be so predomi- 
any Am '"^ ™ assembla ge of drift plants might be furnished by 
stream T^ ^^ ^"'"^ " the Iatitude ° f 5 °° t0 55 ° north ' Bft 
northern Tr 8 ^ ^ "^ '* might dep0sit these P lants in sti11 more 
south t " deS ' as the M 'Ken Z ie river does now. If flowing to the 
Ottawa' th deP ° Sit them t0 the S ° Uth ° f 5 °°- In the Case ° f the 
locality' ^ P could not nave De en derived from a more southern 
f °re saf T* Pr ° babI * v from one ver ? far to the nor t h - w * may there- 
e .v assume that the refrigeration indicated by these plants 
