1016 REPORT —1896. 
therefore no far-fetched supposition to regard the rod-like form of the tubercle 
parasite as an adaptive modification of some higher fungus, existing perhaps as a 
saprophyte outside the animal body. Further support for such a view may be seen 
in the fact that the tubercle fungus occupies a unique position among the patho- 
genic micro-organisms resembling only the well-known hyphomycete Actinomyces. 
The resemban22 of these two forms was pointed out in 1892 by Fischel, and the 
present writer has been able to show that the tubercle organism is accompanied in 
a large proportion of cases by club-shaped growths identical with those so 
characteristic of Actinomycosis. Now it has been placed beyond a doubt that 
Actinomyces is primarily a parasite saprophytic on cereal plants, and that its 
occurrence as an animal parasite can only be regarded as secondary and accidental. 
Whether the change in our view as to the real nature of the tubercle fungus 
will in the future be of any diagnostic value it is impossible to say, as compara- 
tively few cases showing the filamentous growth have yet been observed; but 
there is some evidence in support of the idea that the hyphal type may be 
correlated with more chronic stages of the disease, where actual tissue destruction 
is relatively slight. 
3.1 Preliminary Notes on Florali\Deviations in sone Species oy { Poly- 
gonum. Sy J. W. H.\ Tram, F.R.S., Professor of Botany in the 
Oniversity of Aberdeen. 
The genus has long beent known to show considerable departures from the 
arrangement and number of parts accepted as most typical (Per. 5. St. 5+3, C. 3), 
such as is found in P. convolvulus. Lichler’s ‘ Bliithendiagramme,’ for example, 
shows diagrams of several species as if characterised by constant differences of 
structures. Observation shows that in some species (e.g. Convolvulus) variations 
are comparatively infrequent and slight, but that in most (e.g. Perstcaria and 
aviculare) they are extremely frequent, and lead to very great changes in floral 
structure. Often it is scarcely possible in such species to find two flowers alike on 
the same branch, or even on the same plant. Within a species individual plants 
show wide differences in the frequency and extent of variations. 
A comparison of different species shows that while each varies, so as in the 
more variable species to cover almost the whole range observed in the genus, 
each shows a tendency to certain lines of variation. These tendencies are more 
alike usually in the more nearly allied species, so as to correspond in the main with 
the groups based on habit, and they lead from group to group. 
The modes of variation commonly observed include almost all the recognised 
modes of departure from floral, symmetry. They affect all the whoris. The 
perianth in some species is very constant. In others it habitually shows cohesion 
of two or more segments, or abortion in different degrees, or suppression of one or 
two (usually the inner) segments. Chorisis of a segment is less frequent. 
Enations from one or more segments are frequent in certain species, rare or 
absent in others. The outer stamens often show cohesion of the two in each pair, 
varying from the slightest union of the bases of the filaments to absolute union of 
even the anthers. Abortion (in all degrees to complete suppression) of one or 
more stamens is not rare, frequently reducing this whorl to 3 (less often to 2) in 
aviculare. Chorisis is not rare, especially of the unpaired stamen. The inner 
stamens seldom show cohesion (except in aviculare and its allies) with stamens of 
the outer whorl. Abortion (in all degrees to complete suppression) is very fre- 
quent, and in certain species (amphibiwm) this whorl has completely disappeared. 
In aveulare and allied species the inner whorl shows abortion less than the outer. 
Chorisis in the inner whorl most frequently shows itself in the posterior stamen. 
Adhesions of stamens to perianth segments and petalody of stamens are not 
frequent. 
(In P. amphibium the land form near Aberdeen very generally has the anthers 
very small or abortive, and the stamens hidden within the perianth, while the form 
growing in water has the anthers well developed, and some or all exserted; neither 
form appears to seed habitually.) 
