140 Murphy .— The Morphology and Cytology of the 
lization tubes of abnormal length were mentioned, however, in a preliminary 
paper on this Fungus ( 26 ), and the point deserves reference on that account. 
Such fertilization tubes do occur, but they are quite abnormal. They 
appear to function in the normal manner however. In one case one of 
them was found still embedded in the oosphere and a nucleus lay by its 
tip. The connexion of the tube with the antheridium could not be traced. 
In another case this connexion of a similar tube with its antheridium was 
placed beyond reasonable doubt. Further, it occasionally happens that 
parts of such long, curved tubes are retained within the oospore and there 
coated with a deposit similar in nature to the endospore. This phe¬ 
nomenon has been described by many workers on the cytology of the 
Oomycetes. 
Another abnormality which may be of more significance will be 
mentioned. In this case the antheridial sheath surrounding the stalk of 
the oogonium was developed to such an unusual extent that it entirely 
covered the portion of the stalk within the male organ. Instead of forcing 
the fertilization tube in through the double wall, the antheridium had 
apparently grown out a short distance at one side so as to come into 
contact with the spherical portion of the oogonium, where of course the 
wall consisted of a single layer only. The outgrowth was appreciably 
thinner walled than the remainder of the antheridium, which seems to 
show that it was of later origin. Fertilization had already taken place, 
but the fertilization tube could still be traced running from the outgrowth 
into the oosphere. Only one such case was seen. 
The Oospore. 
As the oosphere contracts a gradual increase in the density and staining 
character of the cytoplasm results (Fig. 28). When fertilization is accom¬ 
plished the cytoplasm begins to take on the appearance common more or 
less to all oospores in the group. It stains more brown than orange and has 
a tendency to accumulate in clumps of a granular nature. The endospore 
is gradually being laid down meanwhile, and while this is going on the 
inner boundary of the wall is never sharp. The endospore consists of two 
layers, named by Stevens ( 34 ) in the case of Albugo Bliti the primary and 
secondary endospore respectively. They are made evident by their staining 
reactions; the former, which is much the thinner,appearing somewhat hyaline, 
the latter staining more deeply with orange G. The mature spore wall 
(Fig. 35) thus consists of three layers: (1) the primitive wall, represented 
by a single stout line, which does not take the orange. This is the first to 
be laid down and is no doubt the last which remains on germination, as 
Pethybridge ( 28 ) has shown. (2) The primary endospore, a thin hyaline 
layer taking orange slightly. This is probably of the nature of a reserve 
