GEMMATION. 



21 



A. Veitchii, A. firma, Picea polita, P. Smithiana, and many others. In 

 other species the bud scales offer the least resistance at the base of the 

 bud, and when this happens, the bud scales are pushed off in the form of 

 a cap. This is observable in Abies bradeata, A. cilicica, A. Pinsapo, 



Picea pungens, P. obovata, and others. 

 Instances have also been observed in 

 which both processes have occurred, 

 as Picea Engelmanni* 



The order of development of the 

 terminal and lateral buds at the end 

 of the erect or of the horizontal 

 shoots should also be noticed. The 

 general but not invariable tendency 

 in the Abietinese is for the side buds 

 to expand before the central or 

 terminal one, even when that is larger 

 than the others. In some of the 

 Pines where the cone is apparently 

 but not really terminal the central bud 

 does not start into growth and develop 

 into a shoot until the originally erect 

 cone bends downwards ; hence the 

 shoot in question is a season behind 

 the cone in development though formed 

 at the same time. 



In Pinus the young shoots present 

 differences which are useful for specific 

 distinction, in colour, degree of hairi- 

 ness, form, etc., some being cylindrical, 

 others with prominent angles with 

 intervening furrows ; but the most 

 remarkable difference is the presence 

 or absence of leaf fascicles at the base 

 of the shoot. When the growth is 

 uniform, the whole length of the shoot 

 is covered with leaf tufts as in Pinus 

 pinea, P. La/'icio, P. sylvestris, P. 

 eontot'ta, P. Cembra, P. riyida and 

 many others ; but when growth is 

 disproportionately rapid near the 

 base, there the base of the shoot is 

 destitute of leaves for some distance, 

 as in Pinus Strobus, P. excelsa, P. 

 Sabiniana, P. Coulteri, P. ponderosa, 

 P. Bunyeana and several others. This 



Fig. 7. Branchlet of Larix europcm Avith 

 tufted foliage. 



* The process of casting off the bud scales is technically called " deperulation. " Dr. 

 Masters calls the first of the two processes described tubular, and the second calyptmte. 

 Instances of tubular deperulation observed by the author occur in Abies homolcpis, A. 

 cepJtahnica, A. balsamea, A. magnified, Picea ajanensis, P. nigra, and many others, 

 including most of the commoner species of Pinus ; and of calyptrate deperulation in Abies 

 sachcde nens is, Picea pungens, P. Engehn/mni, Abietia ( Pseudotsuga) Douglasii, but it is 

 not absolute in all, if in any of these species. In Pinus generally the bud scales are 

 carried forward with the young growth till the leaves are partially developed, when they 

 drop off in centrifugal order. 



