terial, arid generalis (ny rnost honored. friend Fritz Sälen not ex- 

 cepted) the broad botanical know-how, Education f to master the sub - 

 ject., 



You: are correct in seeing the differe^ce between venera dis ~ 

 appear by exarainlng frequently in nature« Scientific Botany will re- 

 duce the nunerous venera foroefully« If we begin to reduce the raass 

 of cacti, the Opuntiae raust be put in. order f Irst , f ollowed nrobably 

 by the Peirescia (Don f t you s.ee any species of this interesting ge- 

 nus.of which Debandolle pictures so rnany nexican species, which sin&e 

 then nobody has seen again and he hinseif only the illustrations) f 

 Then, however, the difficulty starts all of 3 sudden. The Position 

 of the cotyledons is not entirely reliable» as I have seen Cereus 

 fron Cuba with accunbert cotyledons. The seed of (blank space »il.-D. ) 

 to which you ascribe the same , I have not yet examined»- Helocac tus 

 is proba^ly a good. genus.- But fron the giant colunns to the stallest 

 "''••-^' • •-i llariae sone linits have to be drawn; may-be, as nentiored, 

 throriirh the cotyledons. > v 



flower, Inf lorescens, , abundance of flowers, even. the fruit provided 

 a conrlete transition to Rhipsalis 1 ! t And if the floral tube would 

 be even shorter and the seeds not as bumpy t no human being could 

 separate them from Rhip.salis \ This species is the bridge between the 

 txNro genera. Und C. marginatus follows suit, but already nore like 

 Cereizs. 



You rarely mention the tine of day when the flower is open. 

 Night-blooners are probably frequently still open in the norning, 

 thougb. not at noon. When brought into a room for the opening of buds, 

 Observation of the hours of fl owering na y be carried out best, 



The caducous (drooplng, falling off.h.^.) tuft of C. Heppensted ti 

 is a stränge phenonenon. Does it go arourd the entire t T < T ig o^ is it 

 lateral • 



was specially iroportant for ne»because 



