ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 543 



takes occasion to call attention to some results of his own, published 

 in Hungarian in 1876. From a study of the chlorophyll-bodies of 

 Infusoria, he had come to the conclusion that their presence there 

 was not distinctive of any special group of Infusoria. These bodies 

 only occurred in omnivorous species ; and those species in whom 

 they occurred in abundance were noticed to take in no solid food, 

 but only to agitate water in their oesophagus. He characterized 

 these green bodies as Algse, and stated their relation to their hosts as 

 being a perpetual source of nutriment to the latter, which in their turn 

 furnish them with a safe domicile ; the Infusorian supplies the alga 

 with carbonic acid, while the alga produces oxygen for its host. 

 " We have thus to do in this case with a fellowship or peculiar 

 consort relation between two totally different organisms, which may 

 be compared in some respects to the organization of the lichens, 

 which, according to Schwendener's interpretation, owe their existence 

 to the association of a fungus with an alga." Entz has subsequently 

 continued his study of this question, and has been able clearly to see 

 a nucleus in these chlorophyll-bodies, and to determine that the mass 

 is generally invested by a hyaline gelatinous envelope, and thus 

 exhibits all the characteristics of the Palmellacece. He finds that the 

 zoospores of various low Algae and green Flagellates as well may 

 become converted into these " pseudo-chlorophyll-bodies." 



Division of the Cell-nucleus in Spirogyra.* — E. Tangl gives the 

 following results of observations on an undetermined species of 

 Spirogyra : — 



1. The membrane of the cell-nucleus, when at rest, has a reticulate 

 structure; but the author was unable to determine whether this 

 was the result of local differences in density, or of actual perfora- 

 tion. 



2. The nucleus contains, as a rule, only a single nucleolus, and 

 includes, when at rest, besides the nucleolus, a finely granular mass, 

 very poor in substance, and only slightly tinted by colouring re- 

 agents ; the nucleolus is bounded by a membrane which is not 

 tinted. 



3. The nuclear spindle, the formation of which is preceded by 

 demonstrable changes in the contents, is of the type described by 

 Strasburger, and consists of equatorial rod-like elements which are 

 not separated. 



4. The portion of the original contents present in the " spindle- 

 stage" of the nucleus, and only slightly tinted by reagents, is 

 subsequently resorbed during the formation of the daughter-nuclei. 



5. These facts appear to corroborate Strasburger's view that the 

 spindle-fibres are derived from the protoplasm which is forced into 

 the nucleus. 



6. During the separation of the two halves of the nuclear plate 

 a uniting tube is formed, proceeding from the membrane of the 

 nucleus which is already perforated at the two poles at the " spindle- 



* Anzeiger K. Akad. Wiss. Wien, March 30, 1882. See Bot. Centralbl., x. 

 (1882) p. 189. 



