THE INFLUENCE OF MUTILATION ON THE FORM OF PLANTS. 517 



not mutilated afresh, will again put out short catkin-stalks with small pale 

 scales. 



Mutilation of herbaceous plants is caused by herbivorous animals, viz. insects 

 and mammals, and on a large scale by man when he mows the meadows and 

 cuts the crops and makes other necessary invasions on the natural vegetation in 

 the interests of husbandry. The alterations caused by these mutilations of the 

 foliage-leaf region are in the main the same as in woody plants. From the 

 remaining stumps of the stem lateral shoots arise whose first leaves are like the 

 first leaves of the seedling. Usually they are less divided and have fewer hairs 

 than the leaves on shoots of normal plants, and on this account they have a very 

 different character. In the floral region the effects of mutilation are twofold- 

 first the peduncles or the lateral axes which are terminated by inflorescences 

 elongate, and then the flowers become smaller. For example, when a vigorous 

 stalk of the Ox-eye Daisy (Chrysanthemum Leucanthemum) bearing a capitulum 

 is cut off close to the ground, long lank lateral stems develop from the axils of the 

 lowest remaining leaves, each one ending in a capitulum. The main stem is now 

 seen to be branched at its base, which is never the case in normal plants. If about 

 half the stalk of the common Foxglove is cut off in the spring long flower-racemes 

 will arise from the axils of the leaves just below the cut, but the flowers will be 

 only half as large as those which would have developed on the uncut main stem. 

 The stem of Althcea pallida rises a metre above the ground if its development is 

 not hindered, and forms fascicles of short-stalked flowers in the axils of the upper 

 leaves. If the stem is broken off lateral axes develop from the axils of the 

 remaining leaves, and bear little long-stalked flowers. Particularly good examples 

 are furnished by the annual weeds Delphinium Ajacis, Nigella arvensis, Stellera 

 Passerina, and the like, which grow up amongst cereals. Their main stems are 

 broken off when the corn is cut, and they then develop comparatively long 

 branches with small flowers from the remaining stumps. If only single flower- 

 buds, and not the whole inflorescences, are removed from a herbaceous plant whose 

 main stem terminates in a long raceme, so that each flower is cut away in turn 

 from below upwards just before it opens, the rachis of the raceme elongates 

 enormously and flower-buds are developed at its end which would certainly not 

 have unfolded had there been no mutilation. In the Red Foxglove, for example, 

 the rachis of the raceme which has been damaged in this way will grow to twice 

 its ordinary length, and twice as many flowers will be developed. The last and 

 highest flowers in such racemes, however, are only half the size of those which 

 arise on normal racemes. 



We must now consider certain perennial meadow plants which when mown 

 down are stimulated by the mutilation to develop flower-stalks in the same year, 

 which would, in the normal course of things, not have flowered till the year follow- 

 ing. In Alpine valleys it is a very common thing for the flowers of the spring 

 plants Anemone vernalis, Geranium sylvaticum, Gentiana verna, Polygonum 

 Bistorta, Primula elatior and P. farinosa, Trollius Europceus, &c., to appear in 



