6 oo Prankerd.—Notes on the Occurrence of Multinucleate Cells . 
Plant. 
Organ. 
Tissue. 
Nuphar sp. 
peduncle 
ground tissue 
Anona sp. 
cotyledonary node 
cortex 
Ribes sanguineum . . . 
j petiole 
( inflorescence axis 
pith 
Vicia Faba . 
seedling stem 
pith and cortex 
Linum usitatissimum 
plumule 
pith 
Acer Pseudo-Platanus . 
petiole 
ground tissue 
Aesculus Hippocastanum 
bud 
pith and cortex 
Tilia europaea .... 
5 ) 
Hedera Helix .... 
petiole 
ground tissue 
Hottonia palustris . . 
{ bud 
( inflorescence axis 
cortex 
F'raxinus excelsior . . 
>> 
cortex and pith 
Syringa vulgaris . . . 
petiole 
cortex 
Limnanthemum peltatum 
„ 
>> 
Cucurbita Pepo . . . 
hypocotyl 
>> 
Helianthus annuus . . 
)) 
cortex and pith 
In all the above instances the two nuclei were in the same focal plane, 
cases where they were not so being regarded as possibly due to the effect 
produced by the superposition of cells. It must, however, be remembered 
that binucleate cells may be unrecognized by the fact that only one of the 
nuclei is included in the plane of the section, and this consideration is 
of greater importance the higher the number of nuclei in the cell, for the less 
likely will they be all to occur in the same plane (cf. Fig. 7 ). Nevertheless, 
trinucleate cells have been recognized with practical certainty in several of 
the above, e. g. Arum maculatum , Limnanthemumpeltatum^ Zizania aqua- 
tica ; and in Moms nigra (Fig. 1 ) they are obvious and frequent. 
It is very probable that more than three nuclei occur in some cases, and 
in Moms nigra it would be difficult to say sometimes how many nuclei 
a particular cell did contain, for we find what can best perhaps be described as 
a nuclear complex (Fig. 5 ) where a nucleus is dividing into more than 
two daughter-nuclei, or, which amounts to much the same thing, where the 
products of the division of a nucleus are themselves dividing before 
separation. 
Judging from the data at present available, the frequency of occur¬ 
rence of multinucleate cells will be found to vary considerably in different 
plants. In some cases, such as that of Ophioglossum vulgatum , the occur¬ 
rence is very likely rare and sporadic, but in most of the plants mentioned 
above a single section in the appropriate region will reveal several, perhaps 
many instances. The relative frequency of occurrence also varies in 
different tissues. In my experience, pith is far the most likely tissue, after 
this cortex, where they are more often found in the bundle or stelar-sheath— 
a point to which I attach some significance, and which will receive fuller 
treatment in another connexion. Binucleate cells are probably very rare 
in the epidermis, and I have not yet seen them in vascular tissue (see, how¬ 
ever, Arber ( 1 ) and Thompson (7)). With regard to organs, opening buds 
have so far proved the most prolific in showing multinucleate cells; Angio- 
