Classification of BacteriaSystem der Bakterien. Handbuch der Morphologie, Entwickelungsgeschichte und Systematik der Bakterien.W. Migula

E. O. Jordan
1900 Botanical Gazette  
fertilization, the reduction bringing about a return to the ancestral number of chromosomes. Sgpindleformation.-Nemec's recent investigations led him to believe that in vegetative cells the spindle is bipolar from the start, while in spore-mother cells it is at first multipolar. The author objects to this distinction because he thinks that the two forms intergrade. In root tips of Etihedra malor he finds that in the early prophase of division a layer of delicate kinoplasm is formed about the
more » ... leus, and that this layer soon collects at opposite poles of the nucleus, where it appears as a pair of caps, the filamentous nature of which is easily recognized. As the nuclear membrane disappears, threads grow into the cavity, some of them becoming fast to the chromosomes and others forming continuous threads from pole to pole. Since the threads have the same origin and same reaction to reagents, he does not approve the distinction into mantle fibers and central fibers. Centrosomes.-The conclusion is reached that centrosomes are absent from the higher plants, although it is conceded that it would be unscientific to assert that their occurrence here is impossible. Strasburger is inclined, at present, to attribute to the kinoplasm of the higher plants all those functions which it elsewhere shares with the centrosome. Cilia-forming organs.-The existence of blepharoplasts, which he characterizes as specialized masses of kinoplasm, should not be regarded as evidence in favor of a general occurrence of centrosomes among the higher plants. While acknowledging that it would be hard to doubt the centrosome nature of the organ which gives rise to the tail of the animal spermatozoon, he does not think it necessary to assume that the bodies at the base of cilia in animals are centrosomes. The evidence does not point to the existence of similar bodies at the base of the cilia of plant swarm spores and gametes.-CHARLES J. CHAMBERLAIN. Classification of bacteria. Jena: Gustav Fischer, i900.
doi:10.1086/327960 fatcat:ho7fobyt6fdl5f5fbmqqog2zqu