220 The Ottawa Naturalist. [March 



the seed coat in the relative roughness or smoothness of it, and 

 in other characteristics. Those who had previously been 

 sceptical as to the possibility of identifying sppcies of plants with 

 certainty from their seeds alone, were convinced before the 

 meeting was over that this could be done, and that in many 

 cases when the specimens of dried plants were so bad that it 

 was impossible to identify them, a single seed would settle the 

 whole matter. G. M. 



THE CORRELATION OF CHARACTERS IN PLANTS AND 

 ITS ECONOMIC IMPORTANCE TO THE PLANT 



BREEDERS. 



(Synopsis of a Talk Given at a Meeting of the Botanical 



Branch on the Evening of January 8th by 



Mr. L. H. Newman.) 



It is a well known fact that certain characters in plants 

 are more or less closely related and that any modification of 

 the one is simultq,neously followed by a modification of the 

 other. Darwin considered the correlation of different parts of 

 the individual to be an important factor in explaining some of 

 the laws of variation. This tendency for the development of 

 certain parts to follow the developement of certain other parts 

 is of considerable value to the practical plant breeder since 

 his efforts to effect improvement along certain lines may be 

 either offset or assisted by the de\'elopment of other charac- 

 ters elsewhere in response to the disturbance within the organism. 

 The nature of this bond of correlation is not understood al- 

 though several have attempted to explain it. 



Webber has classified the various forms of correlations 

 under four heads, viz.: (1) Environmental, (2) Physiological, 

 (3) Coherital and (4) Morphological. 



Environmental correlation implies merelv the response of a 

 plant to its environment. In other words, .if the soil be poor 

 there will be a correspondingly poor growth ; increase the 

 fertility and the plant immediately responds. 



De Vreis describes this class of variation as one in which 

 two characters react similarly to external conditions. Lieben- 

 berg claims that increase in length of stem is correlated with 

 increase in strength of stem, length of head, number of spikelets 

 and total weight of kernel produced. 



Grains grown under conditions characterized by a super- 

 abundance of light, heat, food or moisture produce extra long 

 heads. In wheat these heads seldom produce more than an 



