3Y2 



THE GARDENER'S MONTHLY 



[ December, 



Our species liius a natural enemy in a small 

 hymenopterous parasite with which I have found 

 certnin of the chrysalids to be filled." 



Respiratiox and Assimilatiox IX Plants.— 

 Corenwinder h!\s recently published an elaborate 

 paper detailing what appears to have been long 

 and careful experiments on the respiration of 

 plants. Protoplasm (the matter out of which 

 cells are made) and chlorophyl (the green color- 

 ing matter in the cell), he finds, have distinct 

 powers. Protoplasm absorbs oxygen and exhales 

 carbonic acid, just as animals do, day and night. 

 In the early stage of plant growth, before much 

 green coloring matter is formed, the plant does 

 little else than exhale. But as soon as chloro- 

 phyl is formed this throws off oxygen and retains 

 the carbon, out of which structure and material 

 for future use is formed. As already known, it 

 can only do this under light. This difference is 

 important, and, while it explains much that has 

 been an enigma, may lead to practical results. 

 Potatoes and other vegetables, sprouting in dark 

 cellars, grow very well, as such a blanched 

 growth grows; but the growth must die, because 

 there is no chlorophyl to manufacture future 

 material. Then we learn why cellars with vege- 

 table growths in them are unhealthy. Plants, 

 as we generally see them, purify the atmosphere. 

 They decompose carbonic acid, appropriating 

 the carbon and expiring the oxj^gen; but in 

 these cases of blanched vegetation the case is re- 

 versed and the oxygen is the element absorbed. 

 There are few papers appearing in scientific 

 journals from which we can learn so much as 

 from this of Corenwinder's. — Independent. 



Artificial Ivory. — The new process for the 

 manufacture of this material have just been 

 brought out in France. The first consists in dis- 

 solving two parts of pure India rubber in thirty- 

 six parts of chloroform, and saturating the solu- 

 tion with pure ammoniacal gas. The chloroform 

 is then distilled at a temperature of 165 degrees 

 Fah., and the residue, mixed with phosphate of 

 lime or carbonate of zinc, is pressed into moulds 

 and dried. When phosphate of lime is used, the 

 product is said to possess in a remarkable degree 

 the peculiar composition of natural ivory. The 

 second process involves the use of paper mache 

 and gelatine combined. Billiard balls of this 

 substance cost about one-third of the price of 

 genuine ivory balls, and are claimed to be quite 

 as hard and elastic as the latter. They may be 

 thrown from high elevations upon pavement 



without injury, and will withstand heavy blows 

 with the hammer. The composition is known 

 as Paris marble, and may be used for raised or- 

 namentation on ceilings or prepared so as to 

 imitate fine varieties of marble. — Gardener'$ 

 Record. 



SCRAPS AND QUERIES. 



Burying Roots. — E. K., Brattleboro, Vt., 

 says : — " Last Spring I had my grounds graded, 

 and about two feet of soil was heaped around a 

 fine larch tree. It has so far not shown any 

 sign of hurt. Fearing, nevertheless, that in might 

 get injured, I beg to ask your kind advice. Tak- 

 ing the soil away to any extent round it, would 

 make a basin into which the water would run 

 from all sides, the tree standing unfortunately in 

 the centre, and is the lowest spot of the ground." 



[Very often trees die after being buried up ; 

 but then again they sometimes live. The chances 

 arc that they will die. They want air — and it 

 may be that in some of the fortunate cases, some 

 of the roots find the way to get air in spite of the 

 covering. In some cases a small walled up well- 

 like circle is made around the trunk of the tree, 

 through which water goes and air follows. This 

 often saves the tree. It is not the filling up of 

 the stem that causes the tree to die, but the suf- 

 focation of the fibrous roots. — Ed. G. M.] 



Freezing of the Sap of Plants. — A Boston 

 correspondent says : — " In the July number of 

 the Gardener's Monthly, page 217, you say ' the sap 

 does not freeze in plants in the winter time,' 

 which seems to me to be a contradiction of what 

 you say upon this matter in the June number of 

 the Gardener's Monthly, page 185, where you say : 

 ' If it has not been long or severely frozen,' re- 

 ferring to a plant, ' it may be recovered by immer- 

 sion in cold water.' If I am in error in regard 

 to this matter will you be so good as to point it 

 out to me as briefly as you please, and at the 

 same time state what it is that injures plants in 

 the winter season, if it is not the freezing and 

 thawing of the sap." 



[Our correspondent has the idea exactly in 

 one way by putting it conversely, " Freezing and 

 thawing of the sap in Winter injures plants." 

 Therefore we say when they are not injured 

 the sap has not been frozen. 



But our correspondent must not forget that 

 plants may die in the Winter from either of two 



