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ANATOMY, AND LIFE-HISTORY OF THE CONIFEKJE. 231 



tigeiium, and by the tension exercised by the growing cotyledons, 

 the husk is thrown off. 



The mode of germination is still unknown in many species. 

 I have had the opportunity, thanks to the assistance of the Di- 

 rector and the Curator of the Eoyal Gardens, Kew, of examining 

 a large number of species ; and for a general statement of the 

 observed phenomena reference may be made to the works of 

 L. C. Richard *, Gceppert t, and to the resume to be found in 

 Sachs's Text-book J, or Goebel §. 



An investigation of the characters of the seedling plant is im- 

 portant not only as occasionally furnishing a means of discrimi- 

 nation, but also as showing vestiges of what has been, and as 

 affording forecasts of what will be. 



The Radicle. — The monopodial radicle is usually slender and 

 tap-shaped, its branches being arranged in two ranks, and given 

 off generally nearly at right angles to the main axis, even in 

 cases where they subsequently descend. The fibrils are often 

 contorted, even when the soil they penetrate is light and open. 



The Moot. — There are considerable differences in the depth to 

 which the tap-roots penetrate, and in the extent and direction of 

 their ramifications, dependent mainly on the character of the soil 

 and the other conditions under which the plants are growing ; 

 though in other cases this direct relationship is not so obvious, 

 lhus, in Pinus silvestris, austriaca, rigida, insignis, in Picea ex- 

 celsa, Sequoia gigantea, Cedrus Deodara, and C. atlantica the main 

 root descends more or less vertically, while the branches spread 

 nearly horizontally. In Pinus Laricio, ponderosa, Abies Pinsapo, 

 Pseudotsuga Douglasii, Thuya gig ant ea, and Cupressus Lawsoniana 

 the secondary roots have a downward direction- In Tsuga Aferten- 

 siana there is less difference in size between the primary and the 

 secondary root-branches than in the Pines ; the root, in fact, is 

 more bushy, and the secondary branches go obliquely downwards. 

 In Taxodium distichum the primary root is relatively extremely 

 long, bright red, with a very few branches which are directed 

 obliquely downwards. As compared with the Deodar ( Cedrus 

 I>eodara\ Cedrus atlantica has a more compact, less-spreading 

 root-system with the secondary branches shorter. The cortex of 





t Gceppert, ■ De 



* L. C. Richard, ■ Comm. Bot. de Ctonif/ (1826). 







book.' ed. Vines (1882). P. 508. 









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