4?32 Variations qfP^iris quadrifbtia, 



the stamens and stigmas in some subvarieties, in which one 

 of these organs exhibited a tendency to subdivide, or become 

 double : by a filament bearing two anthers (j%. 86. c, d^ e) - 

 or by a stigma becoming branched (^and g). By this table it^^ 

 appears that the most common variety (No. 9) exceeds threie^^ 

 fourths of the whole number of the specimens examined ;^* 

 and that No. 16, next in abundance, which differs from it only*^ 

 in having one leaf more, comprises more than half of the ^ 

 remainder. Together, these two varieties exceed nine tenths-^ 

 of the whole. ' 



By Table II. we are shown the liinits, within which the 

 number of parts developed in the separate whorls may lie: 

 and it is very remarkable that these limits are so nearly 3 and ^ 

 6 for the four whorls of leaves, sepals, petals, and stigmas ;'* 

 and that they are nearly 6 and 1 2 for the whorl of stamend.-^'-* 

 There are, in fact, only three varieties wanting out of thef^ 

 twenty-three which such conditions would render possible,'^ 

 and these deficiencies are confined to the non-occurrence of the 'I 

 highest limits assumed for the sepals, petals, and stamens. It 

 should be remarked, also, that although a single instance only 

 has occurred, in any of the flowering stems, in which the first^l 

 whorl was composed of three leaves, this number, however, is 

 very general in the foliaceous whorl that crowns the barren 

 stalks {b). *^ 



Table III. is only a slight modification of Table 11., b«t^ 

 shows us a little more clearly what is the tendency of eack'" 

 whorl to deviate, by excess or default, from its most common 

 condition. 



Supposing, now, by way of hypothesis, we assume the 

 normal character of the plant to be, that it have its several 

 whorls composed of the minimum values which have been 

 observed in the numbering of their separate parts, we should 

 reduce it to the state of a Trillium {h\ an allied genus, 

 which affords as excellent an example of the law of subdivi- 

 sion prevalent among monocotyledons*, as the usual state of 

 Paris quadrifolia is a remarkable exception to it. If we; 

 would now attempt to account for the reason of such an ano-^'* 



* " That the number 3, or a multiple of it, should prevail in the deve- 

 lopement of some part or other of their structure." In the genus Trillium, 

 as the term trillium implies, the parts are all triple ; the leaves are 3; theib 

 sepals (leaflets of the calyx) 3 ; the petals 3 ; the stamens 6, that isy^ 

 twice 3; the stigmas 3; and the cells of the berry 3. (See/g-. 86. h above.) 

 The primordial veins, too, of the leaves, sepals, and petals, both of the 

 species of Trillium and of Paris quadrifolia, are usually three. The species 

 of Trillium are all natives of America, where more than thirty species, it 

 is said, have been discovered; out of this number thirteen species have^a 

 been introduced into British gardens. The figure above (86. h) represents^' 

 Trillium erectum L.^ and is copied from t. 470. of Curtis's Botanical Ma- 

 gazitie, — J. D. 



