SEARCH
0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Prev | Current Page 245 | Next

Vries, Hugo de, 1848-1935

"Species and Varieties, Their Origin by Mutation"

They are not wanting, but only latent.
Basing our discussion concerning the process of crossing on this
conception, and still limiting the discussion to one differentiating
mark, we come to the inference, that this mark is present and active in
the species, and present but dormant in the variety. Thus it is present
in both, and as all other characters not differentiating [255] find
their mates in the cross, so these two will also meet one another. They
will unite just as well as though they were both active or both dormant.
For essentially they are the same, only differing in their degree of
activity. From this we can infer, that in the crossing of varieties, no
unpaired remainder is left, all units combining in pairs exactly as in
ordinary fertilization.
Setting aside the contrast between activity and latency in this single
pair, the procedure in the inter-crossing of varieties is the same as in
ordinary normal fertilization.
Summarizing this discussion we may conclude that in normal fertilization
and in the inter-crossing of varieties all characters are paired, while
in crosses between elementary species the differentiating marks are not
mated.
In order to distinguish these two great types of fertilization we will
use the term bisexual for the one and unisexual for the other.


Pages:
233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257