Occurrence of Foliage-leaves in Ruscus androgynus. 147 



cumstance that these Foliage-leaves in the seedling do not 

 form a continuous series, but are intermingled with scale- 

 leaves ; and the same appears sometimes to hold good 

 when Foliage-leaves occur in the adult plant. The seed- 

 lings have not as yet produced aerial stems. 



In Ruscus racemosus, the seedlings exhibit a number of 

 distichous green scale-leaves forming a rather flat pectin- 

 ate arrangement. As yet no Foliage-leaves have appeared, 

 nor any aerial stem. 



The seedlings of Buscus aculeo.tus, MyrsipJiyllum , and 

 Asparagus have already produced aerial stems, without ex- 

 hibiting any trace of Foliage-leaves. After the hypogeal 

 cotyledon, a few barren scale-leaves appear in the first 

 place ; and these are followed by scale-leaves from the axils 

 of which the characteristic cladodes are produced. It may 

 be that the remote ancestors of these plants possessed 

 Foliage-leaves ; but, if so, these have been completely 

 lost by their descendants. 



In connection with the question of the morphological 

 constitution of the Sciadopitys " needle," and especially 

 with Strasburger's account of its development, above referred 

 to, I must here draw attention to Mr F. 0. Bower's recent 

 observation of the development of the cladode of Rusmis 

 androgymis, as of great importance and significance, " In 

 Ruscus," he says, " the apical part of the phylloelade soon 

 lost its meristematic activity, and the further growth was 

 localised in the basal part of the organ, both in a longitudinal 

 and transverse direction.* From this it will be seen that 

 in an undoubted cladode, such as that of Ruscus, we may 

 have the same early apical arrest, and subsequent inter- 

 calary growth towards the base, as in the Sciadopitys 

 " needle." 



I would here acknowledge my obligations to my 

 demonstrator, Dr J. M. Macfarlane, and to Mr A. D. 

 Eichardson of the Eoyal Botanic Garden, for much valu- 

 able help in the cutting and preparing of the numerous 

 sections required for this investigation. 



* F. 0. Bower, ' ' On the Comparative Morphology of the Leaf in the 

 Vascular Cryptogams and Gvmnosperms." Phil. Trans. Roy. Soc, part ii. 

 1884, p. 601. 



