218 PERSISTENCE OP JUVENILE FORMS. 



occasionally happens that the plant continues to form 

 throughout its existence leaves such as are usually 

 produced only in a young state ; thus M. Gubler (' Bull. 

 Soc. Bot., Fr.,' vol. viii, 1861, p. 527) describes a plant of 

 Pinus pinea in which the primordial, usually transitory, 

 foliage was permanent, leaves of the ordinary shape not 

 being developed at all. It more often happens that 

 some only of the leaves retain their young form while 

 others assume other shapes, see fig. 115. This happens 

 frequently in the larch and constantly in the Chinese 

 juniper when it has arrived at a considerable age. In 

 Cupressus funebris two forms of leaves may often be 

 found on the same plant, the one representing the 

 juvenile state, the other the more developed condition. 

 What is very singular, is that a cutting taken from the 

 branch with leaves of the young form grows up into 

 a shrub bearing leaves of no other shape, so that an 

 ordinary observer unacquainted with the history of 

 the plant would imagine that he had to deal with two 

 distinct species. This fact is the more interesting when 

 compared with the alternation of generations which 

 takes place among the lower animals. 



The regular development of all the parts of the 

 flower in a plant habitually producing irregular flowers 

 is referred to under the head of Peloria, but it still 

 remains to consider those examples in which some 

 only of the parts of the flower are affected in this 

 manner.^ Most of these cases are elsewhere referred 

 to in this volume under the particular form of mal- 

 formation assumed ; but the following case may hero 

 be noticed as not coming under any of the previous 

 heads. It is an instance recorded by Professor 

 Babington (*Phytologist,' August, 1853), and in which 

 the pod of Medlcago maculatay which is usually rolled 

 up like a snail shell and provided with spines, was 

 sickle-shaped and unarmed. 



' See a paper of Professor C. Morren's on " Floral Stesomj " in 

 ' Bull. Acad. Belg.,' t. xix, part ii, p. 519. 



