259 
Its border is often curved, but very irregularly, therefore 
giving the impression of having slips (fig. 4). 
Now we may ask, what is primary? Are those slips 
buildings of a plain border, 
or is the plain border a 
peculiar fusion of the slips. 
If the latter should be 
the case and the slips 
should really have a more 
profoundsignificance, they 
Fig. 4 Ginkgo biloba; young ovules, probably yet stand in con- 
1. micropyle oval, 2. slight indication : É. 
nection with the under- 
of lobes round the micropyle. 
lying anatomical structure. 
On transverse sections through the micropylar region, 
the cavity formed by the integument, in which the nucellar 
beak protrudes, seems to be or oval or triangular. In the 
former case we may suppose that there are two units, 
which may be still fused in two ways: 
of fusion 
N À =. 
 d 
If the slips were the external proofs of such a unit, they 
should occur at the micropyle on places corresponding to:. 
Let us see if this is the case. In the very few cases, 
1 to 10, in which we may speek with some certainty of 
two slips, Î marked the places of the slips, by making 
two lengthwise scratches on the outer surface of the ovule. 
In transverse sections Î saw then, that the places of the 
scratches had no relation whatever to the possible places 
of fusion. In cases with three slips, the situation was the 
same. Therefore wether slips occur on the ovules of 
Ginkgo or not is to my opinion of no morphological 
importance. 
