INCREASING EXOTIC PLANTS FROM CUTTINGS. 169 



INCREASING EXOTIC PLANTS FROM CUTTINGS. 



BY A GERMAN PROPAGATOR IN A LONDON NURSERY. 



My employment from twelve years of age to thirty has been solely in 

 propagating plants in my own country, Belgium, and England. My 

 practice being thus extensive, I take credit for possessing some abilities 

 in the science. This induces me to forward for insertion in the 

 Cabinet some details of my treatment, &c., and for the present 

 Number some remarks on increasing by cuttings shall suffice. 



THE striking OF PLANTS BY CUTTINGS. 



When I obtain cuttings at a distance, I find it inmost cases essential 

 to success to have the ends which have been cut dipped in puddle, or 

 stuck into a portion of clay, for the crude sap in the cutting is not raised 

 by endosmose but by the process of evaporation ; care is therefore 

 taken that the surface of the cut does not become dry before being put 

 in the earth, and air get into the lower end of the vessels, for as soon 

 as this takes place only very strong shoots are capable of drawing up 

 moisture, as has been proved by the experiments of various philo- 

 sopliers. The cuttings are therefore stuck in wet sand, clay, &c., if 

 they cannot immediately be put where they are intended to remain, 

 although it is better to avoid this. If, however, they are such as ought 

 to lie a day or two, in order to insure success, as some acacias, &c., it 

 is in a damp place j and the precaution is taken, if possible, to cut 

 them again before planting. If the long-leaved kinds be stuck in the 

 earth immediately after being taken from the parent plant, the inner 

 bark will become black in from fourteen days to four weeks, and the 

 cutting will perish. 



This phenomenon appears to be in close connexion with the form of 

 the leaves of these plants, as those of the acacias have veiy small 

 stomata. In their stead, on the under side of the leaves of the latter 

 plants, are small dimples, lined with short hairs, which the Diosmas 

 possess. Now, as the crude nourishing matter is draAvn up through 

 the open wood in its existing state, and received by the cutting, wliile 

 the spongioles of the roots only imbibe it in a very thin solution, it 

 appears that the above-named plants, on account of the peculiar 

 formation of their leaves, cannot elaborate in any gi'eat quantity this 

 gross nourishing matter ; and hence arise stagnation of the juices, and 

 the before-mentioned appearances. Tiie good effect of leaving these 

 cuttings lying, and thus interrupting the growing process, and pre- 

 venting the superabundant rise of the crude nourishing matter, will be 

 apparent ; and this is the more probable, as it is usual, for the same 

 reason, to put a piece of mould round the cut. 



Cuttings of succulent or fleshy plants also lie for a time before 

 planting, and on no account in a moist atmosphere, that the surface of 

 the cut may be sufficiently dried. They retain so many watery par- 

 ticles in their cellular tissue that, when this is neglected, the face of 

 the cut soon rots. The species of the families Melocactus, Echino- 

 cactus, Mammiliaria, Opuntia, Cerens, &c., have an extremely thick 

 bark, and a firm epidermis with very few stomata ; on which account 

 the process of evaporation is so slow that they remain alive for a long 



