REMARKS ON THE PHYSIOLOGY OF PLANTS. 87 



ARTICLE VI. 



REMARKS ON THE PHYSIOLOGY OF PLANTS. 



BV OLITOR, CAJIBEKWEI.I.. 



As the physiology of plants is a subject with which all who take an 

 interest in gardening ought to have some knowledge, from its con- 

 nexion with the scientific principles of transplanting, laying, prun- 

 ing, and grafting, I have hastily put together the following remarks, 

 which are at your disposal. 



I have often heard people talk of the sap rising in spring, and fall- 

 ing in autumn, no doubt because they see plants make shoots in the 

 former and cast their leaves in the latter season, whereas sap never 

 falls excepting in the shape of pulp. Sap is supposed to be a fluid 

 taken in by the spongelets of a plant, through which it enters into 

 the root, stem, and leaf; in the last on the upper side only it is 

 changed into pulp, and this passing through the leaf-stalk into the 

 bark, and so into the root, throws out the refuse material from which 

 no nourishment can be derived. It is from this circumstance that so 

 many plants are injured by being tied too tight to flower sticks, by 

 which reason the pulp cannot descend, and consecpuently the sap can- 

 not ascend, so that the plant not being able to receive all its accus- 

 tomed nourishment, or to throw off anything that may be injurious in 

 the pulp, grows sickly, stunted in its growth, and often dies. It is 

 certain that plants take in considerable nourishment during the night 

 in the shape of oxygen, when they throw out a portion of their car- 

 bonic gas, otherwise they could not live so long during the sultrv 

 weather in summer, and become vigorous in so short a time as they 

 do, when life has been thought to be extinct, by the mere application 

 of a little water, and being shaded during the day from the sun. 



If a plant has its leaves and shoots of a dark green, it may be con- 

 sidered more healthy than those of a light colour, from the simple 

 reason that the tube in which the pulp is, being of a yellowish colour 

 and carbon in the sap being of a dark blue, together constitute a 

 n. 



These remarks are perhaps too confused; but should you think the 

 subject worth your attention, I shall be most happy to write a more 

 compact article in any of your numbers. 



[We feel much obliged by the above communication, and shall be 

 glad of ull additional ones. — Conductor.] 



