16 MEYEN ON VEGETABLE IMPREGNATION 
not noticed any distinct organs of motion on these molecules. I 
have, however, nevertheless observed the motion of the sperma- 
tic molecules in many plants in such manner, that it appeared to 
me, and likewise to others who saw their motions, no longer so 
very improbable that these forms likewise are provided with 
some distinct organ of motion, which is however so delicate that 
it is still imperceptible with our present instruments. When, 
. for instance, the spermatozoa of the Mosses are observed lying 
together in large masses, peculiar jumping motions of the ex- 
tremities of their bodies are very often visible, which can only be 
produced by the unrolling of their proboscis; and just such fre- 
quent and remarkably quick movements I have not unfrequently 
noticed in the spermatic molecules of the higher plants, and most 
especially evident in the Cucurbitacee. It is not difficult to arrive 
at such a supposition ; for when Schmidel discovered the sperma- 
tozoa of Jungermannia pusilla, and afterwards also when those of 
some species of Sphagnum were detected, their proboscis was com- 
pletely overlooked, from the lowness of the magnifying power. 
It might also be well to bear in mind that the pollen of many 
plants, in large masses, evinces that remarkable odour which is 
so peculiar to animal sperm; so that we should thence like- 
wise be led to admit that the fovilla of plants corresponds to the 
sperm of animals. 
We will now, lastly, consider some phzenomena attending the 
production of hybrids, which certainly can only be satisfactorily 
explained according to the views that have hitherto been en- 
tertained upon the sexes of plants. It is well known, from the 
multiplying of plants by buds, that the nutritive substance which 
is allowed to pass to an ingrafted or transferred bud, does little, 
or in most cases not at all, alter its specific nature. But if we 
should conclude, according to the new view, that in the produc- 
tion of hybrids the act of impregnation is to be compared t6 
a grafting, the germ of the embryo being merely transferred 
into the tunics of the blossoms of another plant, and requiring 
there only to be nourished,—the important results which C. F, 
Geertner arrived at on the relation [verhalten] of hybrid plants 
cannot be brought into harmony with this view. Above all, 
the new theory is opposed by the observed fact that hybrids 
very usually exhibit a tendency gradually to pass over again into 
the female plant (i.e. that which, according to the old view, is 
called the mother plant !), a phenomenon which has long been 
