in the Inflorescence of Zea Mays. 



217 



with it to which I will here specially direct attention, — 

 namely, the remarkable irregularity observed in the relative 

 arrangement of the male and female florets. The most 

 striking case is presented by one of the secondary axes ; the 

 florets in its basal portion are nearly all converted into 

 more or less perfect females, whilst those above retain in 

 like manner the male characteristics. Associated with the 

 latter, however, and near the upper extremity of the axis, 

 tivo solitciry female florets are at once observable by their 

 prominently developed grains. On examination of the 

 spikelets bearing these, I flnd that the female morpho- 

 genesis is complete, the superior floret alone fertile, the 

 inferior neuter. This individual isolation of the florets, 

 occurring as they do in distinct parts of the axis, and sur- 

 rounded by normal male florets, and perfect metamorphosis, 

 excellently illustrates the occasional independence of such 

 phenomena on mere physical conditions.* 



Thirdly, In specimen No. 4 — a terminal panicle — a some- 

 what different arrangement is observed to that which we 

 have seen followed in specimens Nos. 2 and 3. In the 

 latter two, the basal portions of the axes produce female 

 florets, and the upper male ; whereas in the former. No. 4 

 specimen, the opposite of this occurs, namely, the upper 

 portions of primary and secondary axes converted into com- 

 pact spikes of female florets, while the lower portions, 



* Dr Lindley in treating on tlie changes of sex under tlie influence of ex - 

 ternal causes {Introduction to Botany, vol. ii. 4th ed. p. 80), states "that 

 Mr Knight long ago showed that a high temperature favoured the develop- 

 ment of male flowers, and a low one that of female furthermore, that this 

 eminent horticulturist " entertained little douht that the same fruit-stalka 

 might he made to support either male or female flowers in ohedience to ex- 

 ternal causes." Dr Lindley illustrates these conclusions by experiments on 

 water-melons and cucumbers. From personal observations, however, on 

 several raonoicous plants, I cannot think that these influences are at all 

 definite as to their influence on sex produced. The above laws are still less 

 applicable to dioicous plants"; and certainly, upon any theory of special 

 creation ; on a subjective consideration of the vegetable individual, I fail to see 

 why they should not be equally potent in the one case as in the other. Such 

 cases as those above noticed in the maize, in which collateral florets assume 

 distinct sexual characteristics, induce me to believe that in general the in- 

 fluence of physical condition on the change of sex is subordinate to certain 

 innate, specific, formative qualities ; in short, an inherited tendency to pro- 

 duce the characters in question. 



