EARLY FOLIAGE. 129 



and the leafing of the planes. If we turn to southern latitudes 

 we find that, in Madeira, the planes are leafless in winter ; from 

 the middle to the end of March their buds begin to open ; and 

 at the beginning of April they have flowers and young leaves, 

 which,, however, are fully developed only at the middle of April. 

 Thus the development of the leaves and flowers of the plane (at 

 least in the neighbourhood of Funchal) commences from six 

 weeks to two months earlier than at Zurich. The Swiss Salix 

 fragilis does not occur in Madeira ; but its place is taken by a 

 species (the Canarian willow) which is most nearly related, on 

 the one hand, to the Swiss crack-willow, and on the other to the 

 species of the Miocene, both of which it represents in the 

 Atlantic islands. This Canarian willow certainly begins to 

 flower about a month earlier than the plane ; but its flowering- 

 time lasts much longer, and is continued until the end of April, 

 so that in Madeira the willows and planes are seen at the same 

 time in flower and with fully developed leaves. Here, therefore, 

 these phases of development coincide with each other, because 

 the period of flowering lasts longer, and is not so sharply defined 

 as in more northern latitudes : many trees put forth flowers 

 and fruit throughout the year ; and in those which are limited to 

 particular seasons the transitions are less perceptible and flow 

 more into each other than in temperate climates. That this 

 was the case also in the Miocene district is shown by two slabs 

 w r ith well-preserved willow-flowers and plane-leaves lying side 

 by side, as also by a slab with a female catkin of a willow (Salix 

 Lavateri) and the leaves of the liquidambar. If we may further 

 infer from such facts that these trees bloomed and put forth 

 their leaves at the same period as their existing near allies in 

 Madeira, this period would be about the end of March. It is 

 interesting also to notice the presence of a flower of the camphor- 

 tree lying side by side with flowers of willow and leaves of the 

 plane, as in the gardens of Madeira the camphor-tree flowers 

 exactly at the same time about the end of March. 



We arrive at the same results if we extend our investigations 

 to the flowers of the poplars. The Lombardy poplar begins to 

 flower at Funchal in Madeira at the end of March, therefore at 

 the same time as the plane, whilst in Switzerland and Germany 



VOL. II. K 



