72 BOTANICAL GAZETTE  (yuLy 
Scapania. Mr. WILLIAMS himself (zdem 105-148. ps. 75-24) has enumer- 
ated the mosses, including a new genus (Sryobrittonia) closely related to 
Tortula and Desmatodon, and a number of new species. L. M. UNDERWOOD 
(tdem 148-149). enumerates the pteridophytes ; while the seed plants are 
presented by N. L. BriTTON and P. A. RYDBERG (zdem 149-187), numerous 
new species being described.—P. A. RYDBERG (idem 187-233 Pls. 25- ~337) has 
given an account of the oaks of the continental divide north of Mexico, recog- 
nizing twenty-nine species, nine of which are new.—J. M. C 
PROFESSOR A. B. MACALLUM® has recently added an interesting contri- 
bution to the cytology of certain so-called non-nucleated organisms. His 
work is divided into three parts, each dealing with a separate group of low 
organisms—the Cyanophyceae, Beggiatoa, and the yeast cell—and was 
undertaken with the hope of throwing some light on the origin of the cell 
nucleus, and to obtain data to determine the morphological character of the 
primal life organism. In his investigations Macallum not only used the ordi- 
nary cytological methods, but microchemical tests were also employed to 
advantage. Picric acid and corrosive sublimate afforded the best results as 
carmin, and methylen-blue. The microchemical methods employed for 
obtaining the reactions for ‘masked iron” were practically the same as those 
used in his earlier work published in 1896. The iron liberated by sulfuric 
acid alcohol was converted into Prussian blue, the trichomes were then 
stained with a picro-carmin solution for twenty-four hours, when the cyano- 
phycin granules acquired a deep red color which contrasts markedly with the 
Prussian blue tint of the iron-holding granules. The results obtained on the 
_ Cyanophyceae are briefly as follows. The cell consists of two portions, the 
central body and the peripheral zone holding the pigment. There is no evi- 
dence of the presence of a special chromatophore. There are two types of 
granules present in the cell. The one stains with haematoxylin, contains 
“masked iron” and organic phosphorus, and therefore resembles chromatin. 
The other type is found in the peripheral layer, and chiefly adjacent to the cell 
membrane. It stains with picro-carmin, and is free from organic phosphorus 
and “masked iron.” It is probably a proteid. There is no nucleus or any 
structure which resembles a nucleus in the Cyanophyceae. In Beggiatoa 
there is no differentiation of the cytoplasm into a central body and a periph- 
eral layer, such as Biitschli describes. The compounds of ‘masked iron” 
and organic phosphorus are uniformly diffused throughout the cytoplasm in 
the threads. In the “spirilla,” “comma,” and “coccus"’ forms the cytoplasm 
shows characters like those of the threads, but there are also granules present 
23On the nin ie of non-nucleated organisms. University of Toronto studies. 
Physiological series 2. 1900. 
