PROLIFERATIONS. 259 



e.g. by caterpillars or other insects at a time 

 when considerable stores of reserves had already 

 been accumulated during the period of active 

 assimilation. In such cases the axillary buds, 

 which would normally have passed into a dormant 

 condition over the winter had the leaves lived till 

 the autumn-fall, suddenly shoot out into proleptic 

 shoots (also termed Lammas shoots), and re- 

 clothe the tree with foliage. The wood of the 

 year in which this occurs may exhibit a double 

 annual ring, and the vigour of the tree is likely 

 to suffer in the following season and no fruit 

 be matured. 



Proleptic branches may also be due to the 

 shooting out of accessory buds i.e. extra buds 

 found in or near the leaf-axils of many plants, 

 such as Willow, Maples, Cercis, Robinia, Syringa, 

 Aristolochia, etc. which do not normally come 

 to anything, or do so only if a surplus of food 

 materials is provided. 



Doinnant buds, or preventitious buds, are such as 

 receive no sufficient supply of water and food 

 materials to enable them to open with the 

 other buds in ordinary years, for in most trees 

 only the upper buds on the branches develop 

 into new shoots. The lower buds do not die, 

 however, but merely keep pace with the growth 

 in thickness of the parent branch, and may be 

 elongated sufficiently each year to raise the 

 minute tips level with the bark, their proper 

 cambium only remaining alive but not thickening 

 the bud. 



