68 PLANT HYBRIDIZATION BEFORE MENDEL 



and when they came out, I found they had left behind them sufficient 

 to injj)regn^te those flowers, for they bore good ripe seeds which after- 

 ward§; grew." 



In 1739 appeared a small memoir of thirteen pages, by James 

 Logan, "Supreme Justice and President of the Provincial Council 

 of Pennsylvania in America." This memoir, published in Latin 

 at Leiden and entitled "De Plantarum Generatione Experimenta 

 et Meletemata," contains an account of the author's experiments 

 on the fertilization of Indian corn, and his conclusions on the 

 subject of plant fertilization in general. After a description of the 

 plant, and its manner of flowering, he says: 



"On -the ear appear very beautiful ranks of grains, generally eight, 

 often even ten, and more rarely indeed twelve, and even sixteen I have 

 seen. In any such row, the grains are 40 more or less, which in their 

 rudimentary stage, when the spike is still tender, may rightly be called 

 ova, and upon each ovum arises a slender, delicate, white filament which 

 is also hoUow, and is like a silken thread. These individual threads 

 break through seriatim, between the rows, from the beginning to the 

 ulterior extremity, where, protruding themselves from the leaves which 

 protect the whole ear in a bundle, they appear prominently in the air, 

 in color more often in this prominent part whitish, sometimes indeed, 

 according to the various kind of plant, yellowish, reddish, or purplish ; 

 andi-these filaments, as, I suspected, are presently to be understood as 

 the^true styles of the ova." 



The. experiment in fertilization is described as follows : 



"Therefore, setting about experiments with this plant, in my urban 

 garden, 40 feet in width and about 80 feet in length, from the different 

 corners, having heaped up little hills, according to the method of sow- 

 ing, in the latter part of the month of April, I planted four or five 

 grains of seed (in each). At the beginning of August when the plants 

 had grown to their proper size, and the tassels (cirri) on the summit, 

 and the ears (spicae) on the stalk, had fully appeared, I cut off from 

 one hill all these tassels from within : in others, however, the tassels 

 being intact, I cut off the whole bundle of filaments or styles from -. 

 certain ears, having gently freed them from the enclosing leaves, and 

 covered them again, and from others cut one-fourth, and others left / 

 intact. Another ear, before the bundle (of styles) should get to the 

 light, I gently wrapped in a light, soft cloth of Indian or Chinese linen, 

 called by us 'muslin,' and so loosely that not the least injury should 

 happen to the vegetation, so that, on account of the lightness of the 

 cloth, the ear should enjoy the benefit of the sun, the air and the 

 showers, but that on account of the woolly cloth it would be exposed 

 to no approach of the pollen. Four hills I left whole and intact, and 

 as many of the others also as possible, in that condition which I have 

 stated, I permitted to come to the time of maturity, (pp. 8-9.) 



"Towards October, it was seen that in the first hill, which had been 

 completely detasselled, although the ears were satisfactory to the eye, 

 not a single grain was matured, except in a single ear of greater size, 



