70 COMPARATIVE EMBRYOLOGY OF THE RUBIACEAE 
degree the multipolar spindle primordium in plants, to which the 
author unhesitatingly compares it, with the inference that the 
plant cytologists have still overlooked the structures in question. 
'But the comparison is without warrant, for an examination of the 
facts shows that we are dealing with two different modes of action. 
The origin of the spindle is in the two cases quite different. 
In Paludina it is in the periphery of the cell, while in the higher 
plants it is at the nucleus. The development of the spindle is in 
the former therefore centripetal; in the latter centrifugal. We 
fail therefore to see any warrant for the conclusion that there is 
any parallel between the phenomena described by Meves, and 
those seen in the formation of the plant spindle of multipolar origin. 
The parallel fails also in the following regard. In Paludina 
the spindle fibers develop from the centers. In plants, even ad- 
mitting the existence of centers, the fibers are developed to a very 
considerable degree before the centrosomes, or centrosome-like 
bodies, when such are recognized, appear. 
For the present, therefore, we must adhere to the view that 
the centrosome is absent from the higher plants. 
We do not attempt to meet in detail the statements in certain 
recent papers to the contrary. * It is quite impossible to do this 
except by working with the same materials and methods, and this 
has not been done by me. 
Nor, as Strasburger (/ c.) has shown, is positive evidence 
against the occurrence of the centrosome in higher plants want- 
ing. Repeated studies on pollen development have been carried 
out, showing that the ends of the spindle find an insertion in the 
ectoplasm and the results of my own observations tend strongly to 
confirm the view that the ectoplasm serves in many instances as a 
place of connection in those cells in which the spindle is long 
enough to bridge the distance from side to side. One instance 
(Asperula) was seen in which a pluripolar diarch spindle had its 
four apices (appearing in a single section) were all inserted in the 
bct Los 9, fig. 16). 
— ME E M M 
Bernard, Ch. Recherches sur les sphere attractions chez Lilium candidum, 
Helosis ری‎ etc. Jour. de Bot. 14: 118, 177, 206. 1900, 
amanuochi, S. Einige وس ور‎ uber die Centrosomen in den Pollen- 
mueren von Lilium longiflorum. Bot. Centralbl. Beihefi fte, 10: 301. 1901. 
. H. ۸ Contribution to the Life Histo 
ry and cytology of Erythronium. 
Bot. Gaz. i DN June, 1901. ytoiogy 7 
