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ANATOMY, ANJ) LIFE-HISTORY OF THE CONIFERS. 241 



bud marks the termination of the first stage of growth. When 

 the axis lengthens, the primordial leaves, instead of being tufted 

 are either scattered as in Sequoia gigantea, where they are alter- 

 nate, or arranged in decussate pairs, each pair being separated 

 by an intern ode from that above and that below, as in Scia- 

 dopitys, Taxus, Ginkgo, Cupressus, Callitrw, Frenela, Araucaria 

 «pp., Libocedrus, Cedrus, Phyllocladas, Thuya, Picea Menziesii, 

 and Oryptomeria. In some of these plants axillary buds may be 

 seen in the axils of the primordial leaves, the first two leaves of 

 these buds being placed at right angles to the primordial leaf. 

 The upper part of the plumule in Pinus Torreyana and Retino- 

 spora pisifera is conoid, compressed from front to back, and 

 depressed at the apex owing to the projection on either side of a 

 leaf-tubercle * 



In a specimen of Oephalotaxm Fortunei in the Kew Museum, 

 above the cotyledons and in close proximity to them is a pair of 

 opposite leaves followed after an interval by a whorl of four linear 

 leaves rather larger than the preceding, then after another inter- 

 space occur two leaves succeeded in a decussate manner by two 

 others. In this plant the plumule emerges from the seed before 

 the cotyledons are disengaged from the seed-coat. The primor- 

 dial leaves are either free at the base, as in Betinospora obtusa, &c, 

 or concrescent f with the stem and uplifted with it, as in Cupressus 

 senipervirens, Abies Veitchii, and Oryptomeria japonica. 



These observations relating to the seedling plant have necessarily 

 been made on a limited number of examples ; care must there- 

 fore be exercised in drawing inferences from them, the more so 

 as some of the peculiarities mentioned are manifestations of 

 relative degrees of vigour dependent on external conditions J. 



Dingier, as cited in the ' Botanical Gazette,' May 1883, p. 229, assert* that 

 m seedling Gyinnosperms there is, as in Cryptogams, a single apical cell, instead 

 * » group of cells at the apex of the growing-point as happens in Flowering 

 Wants, but this needs confirmation. 



t The word " concrescent " is adopted by M. Van Tieghem, and seems to be 

 c <>»mng into general use to express the condition formerly, but erroneously, 

 *T ed adnation, and by myself " inseparation," as denoting that kind of arrest 

 developmental change indicated by imperfect separation of two parts. The 



arrest of development in these cases is associated with rapidity and vigour of 

 growth. 



+ it may be convenient to append in this place references to various works in 



W AM ^ m0de ° f S erminafcion of different species is figured :— 



tes tehamea, pectinata. Pinsavo. Duchartre in Ann. Sc. Nat. ser. 3, t. x. 







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