R H. CoMPTON 69 



Italian Millet. 



The seedling of Setaria italica exhibits a long internode between 

 the scutellum and the base of the plumular sheath (cf. Maize). 

 A number of seedlings were counted, and there were found 258 with 

 the first leaf folded in the left-handed, 217 in the right-handed fashion. 

 Ratio LH I RE = 119 (5^1 °I^LH). A marked excess of left-handed 

 seedlings occui-s here also, though not so great as in Barley. 



Rye. 



Secale cereale is an unfavourable plant for this purpose, owing to 

 the narrowness of the leaves and the frequency with which both 

 margins are curled inwards in the upper portion^ Out of 30 seedlings, 

 16 were LH and 14 RH : showing that both conditions occur here 

 also, though the numbers are insuflBcient to allow a ratio to be 

 calculated. 



Maize. 



As is well known, the infructescence or cob of Zea Mais is com- 

 parable with an annular fasciation : its construction is such as might be 

 obtained by the fusion in a cylinder of a number of pairs of rows of 

 fruits *. The number of such double rows varies from 2 to 1 1 according 

 to the variety and the strength of the plant. In every case it is easy to 

 distinguish the rows of a single pair from the adjacent rows of con- 

 tiguous pairs. There is a shallow furrow on the cob between adjoining 

 double-rows which becomes evident if the cob be cut or broken across, 

 though it is usually impossible to see it in the ordinary condition owing 

 to distortion of the rows at the ends of the cob. It is said that the 

 Maize cob invariably possesses an even number of rows of grain : this 

 being of course the result of its construction from pairs of orthostichies. 



In speaking of the Maize cob I propose to distinguish odd and even 

 rows of seeds, in the same way as in Barley : for it may be considered 

 as in a sense equivalent to a fused ring of ears of two-rowed Barley*. 

 Holding a Maize cob upright, and considering a single pair of rows of 

 grain towards the observer, that row which is towards his left hand will 

 be called odd, and that row even which is towards his right hand. 



1 Cf. Compton, 1910, p. 496, first foot-note. 



' Another case of an hereditary ring-fasciation is described in my paper on "The 

 Anatomy of the Mummy Pea," New Phytologist, x. p. 249, 1911. 



* Hackel (loc. cit. p. 20) remarks that "die einzelnen Doppelzeilen je Einer Aehre Ton 

 Eachlaena entsprechen. " 



