iS4 



not the scientific botanist, and therefore use as simple terms 

 as possible ; and in the second place I am quite incapable, in 

 view of the facts, of comprehending the objections. In 

 both the flowering plant and the Fern prothallus we find a 

 similar chain of cause and effect. In the flowering plant 

 the future seed vessel contains at first unfertilized cells, from 

 which part of the vital nucleus has been removed to make 

 way for an independent part, subsequently provided from 

 the equally diminished pollen or male cell. In the process 

 of fertilization these two half nuclei are brought into con- 

 junction and so form a perfect cell, which is then enabled 

 to divide and multiply, forming in the process a perfect 

 seed, which eventually reproduces the plant. The seed 

 here is capable of detachment, and of being scattered 

 abroad to propagate its kind. In the Fern the detachable 

 propagating body, the spore, is an unfertilized cell protected 

 by a coat or husk. By virtue of this unfertilized condition 

 it is incapable (except under abnormal circumstances to 

 which I will refer later) of direct reproduction, but when 

 it finds suitable conditions where it becomes deposited, it 

 produces a small flat green scale attached to the soil by 

 roothairs, and on the underside of this there are generated 

 two sets of organs, male and female [anther idia and 

 archegonia). The male ones are tiny pimple-like bodies, and 

 the female ones small elevated hollow teat-like bodies, at 

 the base of each of which, embedded there in the thickened 

 body of the scale, is a cell. This cell, like that of the 

 embro seed, has only half a nucleus. When ripe the male 

 bodies burst and emit a swarm of small swimming tadpole- 

 like organisms, in the head of each of which is a similar cell 

 also deprived of half its nucleus. We have here, to my 

 mind, an exactly paralled case to that of the flower, since 

 eventually the two half nuclei come together, the male 

 germ travelling to and thus reaching the female one. This 

 junction being effected the reproductive female cell is com- 

 pleted, divides and redivides, produces a root and a frond 

 with a basal bud, and thus reproduces the Fern precisely 



