17 
ing so closely appressed to the anther. When, now, we read that the 
anther in Pyrolineae is " normally extrorse in the bud " and that the 
pores are *' really basal," the ordinary inference must be that it is this 
folding of the filament that constitutes the normal condition, and 
renders the pores truly basal. But again we are puzzled on finding 
that this same folding of the filament, producing reversion of the an- 
ther, in the bud, prevails in a number of genera of Ericinejie, partic- 
ularly in the first and second tribes- Why then shouldlhe same con- 
dition be called normal in one case and abnormal in the other? Why 
should pores similarly placed be called basal in the one sub-order 
and apical in the other? Why should Arctostaphylos and Arbutus 
form one extreme, and Clethra and Pyrola tlie other, of a large family, 
the intervening genera differing in the'most important characteristic 
in which these extremes agree? An answer is found in the existence 
in the Pyroline^ of a second fold or turn of the filament at its point 
of attachnTent, thus placing it erect in the bud, and inverted in the 
flower, when the larger first fold has become obliterated. A careful 
study of this sul)ject has proven so interesting that my observations 
nave been committed to paper, and, with a few diagrams, are here given. 
Fig. I, 
Fig. 2 
Fig. 3. 
Fig. 4. 
I shall speak of the primary, obscure fold in Pyrolinese as an inversion^ 
^l^ich it really is,. and the more evident, secondary fold, common to 
many genera, as a reversion. Suitable buds for this study not being 
commonly collected, I heve been unable to examine some genera at 
^11, and in several others the buds were so old as to leave the truth 
merely inferential. 
Inversion has been clearly demonstrated in Clethra^ Chifnaphila 
2nd Pyrola — Moneses not having been examined. 
Reversion is certainly present in Arbiitus, Arctoslaphylos and Cas- 
^^ope^ and probably in Gaultheria and CassamTra. It has been 
excluded in Leucothoe, Oxydendron^ Epigcea, '^Andr^meda^ Caliuna, 
Ledum and Rhododendron. IxTAfenziesiayl^o far as "my observations 
8^. it is very doubtful, and the otlTer genera I have had no opportu- 
i^Uy of examining. 
My observations began with the study of Arctostaphylos, in Feb- 
niary, 1881, when among the mountains of South-eastern Arizona I 
^as waiting for the spring flowers to open, only Ardoslaphylos pungens, 
J^fiK., Brodicea pauciflora, Wats., and Carphochceta Bigelovii, Gray, 
being in flower, 
The drawings made at that time are lost, but the plan of reversion 
