OF THE 



UNIVERSITY 



OF 



UNIVERSITY OF CALIFORNIA PUBLICATIONS 

 BOTANY 



Vol. 2, No. 12, pp. 237-296, Pis. 21-26 November 10, 1906 



CYTOLOGICAL STUDIES IN CYANOPHYCEAE 



BY 



NATHANIEL LYON GAEDNEE. 



CONTENTS. 



PAGE 



I. Introduction and Technique 237 



(a) Species Studied 239 



(b) Collecting and Preparing Material : 240 



(c) Killing and Fixing Agents 245 



(d) Stains and Staining 245 



II. Eecent Literature 249 



III. The Cell Contents 259 



(a) The Nucleus 260 



(b) The Granules _ 269 



(c) The Cytoplasm 273 



IV. The Products of Assimilation 274 



V. Experimental Cultures 275 



VI. The Eelation of Cyanophyceae to Bacteria 278 



VII. Eesults 280 



VIII. Summary 281 



TX. Bibliography ; 283 



X. Explanation of Plates 286 



I. INTRODUCTION AND TECHNIQUE. 



The somewhat aberrant group of plants known as the Cyano- 

 phyceae possesses many exceedingly interesting features, whether 

 considered from a systematic, a physiological, or a cytological 

 standpoint. These plants are representatives of a very ancient 

 group which has adapted itself to the most diverse habitats while 

 retaining its original simplicity of structure. They abound in 

 the cold waters of the north, in the hot springs of the Yellowstone, 

 of New Zealand, and of other parts of the world, where the tem- 

 perature of the water is near the boiling-point; they grow in 

 shaded places and in the open glare of the sun ; are encrusted by 



172911 



