Ward. — Recent Researches on the Parasitism of Fungi. 35 
und Untersuchungen unterliegt es fur uns keinem Zweifel, dass das intra- 
cellulare Mycoplasma und das intercellulare Protomycelium genetisch zusam- 
mengehoren. Nur'sind die Einzelheiten im Ubergang von jenem zu diesem 
Stadium noch nicht so vollstandig und genugend aufgeklart worden, dass 
wir jetzt auf diese Ubergangsfrage naher eingehen konnen oder wollen.’ 
Eriksson then describes (66, Taf. II, Fig. 11 a and b) what he regards 
as swollen nuclei of the host-cells. 
Before proceeding further, I may again remark on the one curious 
omission in all Eriksson’s work. Nowhere, so far as I can discover, does 
he trace his Fungus from the infection-spot, and in no case has he given 
a figure of the germ-tube entering the stoma, and compared the phenomena 
with what he finds elsewhere. True, he denies that the investigation of 
infection by means of spores is the right way to go to work; but one 
would have thought that it was at least necessary to compare and contrast 
what happens in normal infection with what is alleged to take place 
independently of it. Moreover, as was clearly shown in my paper on the 
histology of P. dispersa , Eriksson would have avoided some important 
errors had a strict comparative investigation been made; and the appli- 
cation of this to the histology of P. glumarum leads us to the same 
conclusion. 
The Histology of Puccini a Glumarum. 
Assisted by Mr. Evans, I have for some time been occupied with 
the histology of P . glumarum in Wheat, under various conditions of growth, 
normal as well as abnormal ; and I would take this opportunity of saying 
that Mr. Evans has independently worked out the normal life-history 
and histology in the most thorough manner, as well as helped my part 
of the work to such an extent that we may regard it as practically conjoint. 
The results may be briefly summarized as follows 
The uredospore of P. glumarum germinates on Wheat, and infects 
it by means of a germ-tube which enters the stoma and puts forth an 
infection-tube from a vesicle, exactly as in the case of P. dispersa on 
the Bromes. 
The sub-stomatal vesicle and the infecting hypha sent out from it are, 
however, very different in detail from those of P. glumarum , the vesicle 
having a firmer cell-wall and more numerous nuclei, and the infecting 
hypha being of far greater diameter and containing very many brightly 
staining nuclei. 
Soon after entering the stoma, and having formed the sub-stomatal 
vesicle, the infection-tube put out from the latter forms its first haustorium, 
and the further growth takes place much as in P. dispersa. 
The most remarkable points in these young hyphae are their great 
diameter (from 3-4 up to 18 /x and more), the rarity of septa, the abundance 
