62 THE BRITISH NATURALIST. [March 



processes of fertilisation are hidden or concealed. The perusal of this 

 curious chapter of nature's volume has only been attempted in quite 

 recent years. It was the painstaking genius of the late Charles Darwin 

 that first popularised it to the average botanist. The veriest tyro in Botany 

 knows the functions of the various parts of the flower. The calyx and 

 corolla, to shield or protect the more delicate essential organs ; the 

 stamens, containing the pollen, which has to be conveyed to the stigma in 

 order that fertilisation may be accomplished and seeds produced. This 

 process is usually very obviously performed, and the showy flowers 

 and attractive blossoms are all necessary for their proper functions. 

 The ordinary observer is very apt to overlook those plants in 

 which there are no conspicuous blossoms, but there is quite a 

 number of plants which, besides producing a series of well-developed 

 flowers, at another stage also bear blossoms which never expand at all. 

 One of the most familiar and striking examples is furnished by the com- 

 mon Wood Sorrel yOxalis acetosella) of our woods and lanes. In early 

 Spring it produces an abundance of its pearly white and delicately veined 

 blossoms, nestling amongst its lovely green trifoliate heart-shaped leaves, 

 which makes it often taken for the type of the Shamrock. These Spring 

 blooms are showy, handsome and attractive, and also less or more fertile. 

 But besides these it forms in Summer low down near the roots, indeed 

 frequently buried in the soil, minute flowers which never expand at all, 

 but yet produce abundance of seeds ; indeed they are far more prolific 

 than the earlier and gaudier blossoms. These cleistogamous flowers 

 are produced at the least possible expenditure of vital force by the plant. 

 There is no large showy corolla to manufacture, nor a profuse amount of 

 pollen the bulk of which is wasted ; but only a few grains of pollen are 

 formed, which are conveyed direct to the stigma, and there perform their 

 function of fertilising the pistil without any waste of energy or 

 material ; and cleistogamous flowers invariably develop a large number 

 of perfect seeds. The well-known Sweet-scented Violet [Viola odorata), 

 which adds such a charm by its fragrance to our English lanes in Spring, 

 also produces these concealed flowers in Summer. The fragrant blooms 

 of Spring are only sparingly fertile, so the plant is largely dependent on 

 these obscure flowers for its seed supply. Anyone can detect these for 

 themselves ; they appear like minute buds at the extremity of the flower 

 stalks, arid more closely resemble the mature seed vessels than unex- 

 panded flower buds ; they are usually quite hidden by the leaves and 

 require to be searched for. The Red Dead Nettle (Lamium purpureum)> 

 and its congener the Henbit Dead Nettle (L. amplexicaiile), common 

 garden weeds, also furnish familiar examples of this most interesting floral 

 freak. 



