88 PLANT LIFE. 



at its narrow end to the stem. Hence rain and soil 

 particles slip down over them, and cannot injure the 

 delicate tissue within. 



Many of these young developing leaves show a 

 characteristic slimy or guininy secretion. This is parti- 

 cularly distinct in the young dock or sorrel. The 

 internodes are at first very short, and the young leaf, 

 which has the thin green parts neatly rolled up on 

 either side of the midrib, is enclosed in the stipule- 

 sJieatJi ; it is also very slimy, and the exposed parts are 

 often red. Both this colour and the mucilage are 

 protective ; probably the slimy or mucilaginous matter 

 prevents loss of water whilst the leaf is young, and at 

 the same time also prevents any harm arising from its 

 being rubbed, whilst still delicate, against the stiff edges 

 of the sheath. Other cases which show (according to 

 Dr. Hunger) the same mucilaginous oiling of the young 

 parts to prevent injury by friction are the young leaves 

 of Ranunculus ficaria^ Viola silvestids^ and Chenopodium 

 Bon us- Hen ricus. 



Every sort of protection is required in early spring ; 

 because, if the weather is too dry, germination cannot 

 take place, whilst, if it is too wet, there are hundreds of 

 fungus spores ready to attack the young leaves before 

 they have had time to form their hard protecting skins. 

 Such fungi as Pythiuni de Baryanuni may destroy whole 

 beds of seedlings, or PJiytophora oninivora may attack 

 the cotyledons of young beeches and destroy every 

 plant in a nursery. It is important to remember that 

 every plant in such a complex system as a Grass 

 meadow has to suit not only its adult but also its 

 seedling environment. 



For mankind these food stores are, of course, ab- 

 solutely necessary. The amount yielded by different 



