48 
Embryosack nehmen die Spindeln eine schiefe Stellung zur 
Langsachse des Embryosackes ein“ states Paum. This deviation 
from the ordinary condition and still more the vacuoles originating 
in two distinct groups strongly influences the character of the 
embryo sac. The figures themselves seem to suggest that there 
are two developing megaspores. 
Both megaspores develop their full number of eight nuclei. 
Owing to the narrowness of the Pyrethrum sac the nuclei of 
the different groups do not mix up. The sac thus presents a 
row of four groups of four nuclei each, in fact a row of two 
eight-nucleate embryosacs. 
In the upper one the nuclei are arranged in the ordinary 
way, there being two synergids, an egg, two fusing polar nuclei, 
and three antipodals. By these three antipodal cells the narrow 
sac is barricaded so that communication between the upper 
and the lower half is made impossible. In the lower sac the 
behaviour of the nuclei is somewhat abnormal. Four of them 
separated by cell walls are to be seen just below the three 
antipodals mentioned. The other four remain free in the sac 
cavity. Perhaps, however, no mature sacs are seen by the 
author, as Patm says: “Ueber die spiitere Entwickelung dieser 
eigenartigen Zelle gibt leider mein Material keine sichere Aus- 
kunft.“ As far as present knowledge reaches the formula must 
be Cc—I—la. (fig. 12, p. 43). 
Pyrethrum thus closely agrees with the related Tanacetum 
(Parm 1915). In both the details of the development are the 
same, the only difference being the somewhat further reduced 
stage of the Tanacetum embryosac, in which only four nuclei 
are developed by the lower megaspore. It is almost incredible 
how Patm, who has been struck himself by this strong agree- 
‘ ment, could have been so fascinated by the idea of the “1G4 
nucleate type“ that he, in spite of relationship and agreement, 
separated Pyrethrum from Tanacetum and classified it in the 
same group as Peperomia, Penaeceae, etc. 
Limnocharis emarginata has been investigated twice. We can 
pass Ha1x’s publication (1902) on the subject, as his improbable 
statement of the life-history was proved to be false by NirascHkE 
