34 MARKET NURSERY WORK 



to replace them after a few minutes, though he may find it quite 

 necessary to leave a small vent on for probably an hour. This 

 was our own invariable custom, for pains must be taken just as 

 much to prevent excessive moisture as are taken to prevent aridity. 



A temperature above that we have stated may become dangerous 

 in exciting the scion into growth before it has become sufficiently 

 incorporated with the stock to draw nourishment from it. This 

 is almost bound to happen to a certain extent, though the percentage 

 of precocious growths is very small, but when it does happen 

 it generally proves fatal unless the subsidiary side eyes are able to 

 take up the running when the active centre eye has given up. 

 If then a dangerously high temperature threatens, through erratic 

 stoking or any other cause, a wedge must be inserted under the 

 front of the lights to create a vent for as long a period as is necessary 

 to reduce the temperature to the normal. Really, growth must 

 not be forced, for forced growth is weak growth, and if the bottom 

 heat is too strong it is a bad preparation for young plants which 

 in the course of a few days may have to stand on stages where 

 no bottom heat is provided. 



In about a fortnight after grafting it will be seen that the stock 

 is forming a callus and endeavouring to recover itself from the rude 

 beheading and cutting to which it was subjected (see Fig. 18). 

 This " callus " is formed by the exudation of sap along the lines 

 of the " cambium," before explained, and in this endeavour to 

 recover itself it incidentally embraces and joins itself to the scion, 

 or it might be more correct to say it joins the scion to itself because 

 the eye of the scion can alone provide an outlet for its energy. 

 In its struggle to live its own life it will from time to time produce 

 eyes, somewhere or other, even if it be on the root itself, but these 

 are removed as soon as they appear, and the energies of the stock, 

 willy-nilly, are driven into the scion as its only means of life. This 

 process of union may take some time to thoroughly complete itself ; 

 sometimes a whole season passes before it can be said to be perfect 

 and real fusion achieved, and this will suggest to any reader that 

 the whole of the season must be, more or less, a time of nursing 

 for the plant. 



When the graft has fairly taken and begins to unfold its first 

 leaves (see Fig. 19) it must be removed from the frame, or the great 



