40 Hans Winkler. 
in different countries, between Zygopetalum and several more or less 
remote genera, with the result that all the offspring have proved to 
be Zygopetalum pure and simple. Altogether more than 400 seed- 
lings have been raised. 'T'he seed-parent in each case was Zygopetahım 
Mackayi (the reserve crosses being unsuccessful). The pollen used was 
from Odontoglossum Pescatorei, ©. crispum, ©. grande, ©. bietonense, 
Oneidium tigrinum, Lycaste Skinneri, Laelia anceps, Calanthe vestita and 
Vanda caerulea. All the 400 seedlings raised from these matings 
proved to be exactly like the seed-parent, Z. Mackayi. It is inter- 
esting to note, however, that the individuals raised from the same 
capsule varied in size and colour of the flowers in the same way 
that the seed-parent species does in its native habitat. 
In other words, the „false hybrids“ behaved just as if they had 
been raised from self-fertilised seeds; but, as I showed in 1898. self- 
fertilisation, direct or indirect, was impossible in these cases, as the 
pollinia of the seed-parents were all carefully removed, before the 
crosses were made. Apart from this, too, the peculiar structure of 
these Orchids makes self-fertilisation impracticable. as Darwin has 
well shown. Nor is it apparently a case of Mendelian dominance, 
for in the second generation (F2) the characters of the seed-parent 
are again repeated pure and simple, even when the „false hybrid“ is 
re-mated with the supposed recessive. This experiment was carried 
out by Mr. MeWilliam, by re-mating one of the F1 „false hybrids“ 
(Z. Mackayi 2» L. anceps) with pollen of L. anceps alba, and the 
result was still Z. Mackayi pure and simple. 
It seems clear, therefore, that we have in these Zygopetalum 
seedlings, „false hybrids“, comparable to the original ones of Mil- 
lardet (1894) in Fragaria. It may be noted that all the „false 
hybrids“ in Orchids so far are maternal in all characters, as were the 
majority of Millardet’s, and also Bateson and Saunder’s Mat- 
thiola. Other experiments, however, show that „false hybrids“ may 
oceur that are paternal in all characters, as ina few of Millardet’s 
Fragaria and de Vries Oenothera. 
Whether all these types of „false hybrids“ have a common ex- 
planation is difficult to say. but so far as the Zygopetalum series is 
concerned, in 1900 I suggested that the stimulus of fertilisation might 
induce a kind of parthenogensis, without actual union of the sexual 
elements, causing the „false hybrids“ to resemble the seed-parent in 
all characters“. 
Diese Ansicht von Hurst, die ja in der Tat eine sehr nahe- 
liegende und plausible Erklärung für das eigentümliche Verhalten 
der Zygopetalum-,„Bastarde“ darstellt, und die auch von vielen anderen 
Forschern geteilt wird, bedarf natürlich noch der Bestätigung durch 
die cytologische Untersuchung, die sehr erwünscht wäre. Was sie 
