Notes . 
431 
to the question whether there is blaze and germination. As regards 
the lower degrees and the smaller differences of vitality, the chances 
of disagreement between the two tests are obviously greater. As 
regards the electrical test, it is more difficult to take the measure 
upon the entire seed than upon its isolated radicle. As regards the 
germination test, it is not always easy to ensure identical and optimum 
conditions. 
Fresh and vigorous seeds manifest a large blaze response (0-0500 
volt or more), and germinate strongly. Older and less vigorous seeds 
manifest a smaller blaze (o-oioo volt or less), and a less active 
germination. Still older seeds, incapable of germination under even 
the most favourable conditions, manifest still smaller blaze (o-ooio 
volt or less), and finally none at all, or the small counter-effect due to 
polarization (0-0005 volt more or less). 
THE QUADRIPOLAR SPINDLE IN THE SPORE-MOTHER- 
CELL OF PELLIA EPIPHYLLA.— I have read with interest the 
account of nuclear division in Pellia as given by Prof. Davis in the 
last number of this journal \ and it is a source of gratification to find 
that his description of the processes accords so nearly, at any rate as 
regards matters of fact, with that given by me in 1894 and 1895 2 . 
But in dealing with the first mitosis in the spore-mother-cell, he has 
arrived at conclusions respecting the peculiar spindle so characteristic 
of the earlier stages, which diverge considerably from those which 
I expressed in the second paper above cited. As the matter is not 
merely one of detail only, but is of great cytological interest, it seems 
desirable briefly to examine the evidence adduced by Prof. Davis in 
support of his own contention. 
He apparently regards the quadripolar spindle, described by me, as 
non-existent (‘there is no four-poled spindle/ p. 174), and he was not 
able to trace any structures in the cell of the nature of centrosomes 
in connexion with the mitosis under consideration. The first of these 
objections seems to depend chiefly on the mode of interpretation 
adopted, the latter more nearly touches upon fact. 
Now, as regards the failure to identify the centrospheres at this 
stage, I can only assert that they are certainly to be distinguished 
in appropriately prepared sections, although they are by no means 
1 Annals of Botany, xv, No. LVII. 
2 Ibid., viii and ix. 
