ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 605 



The systematic disposition of this group is next considered, and is 

 followed by the systematic description of its divisions, the whole work with 

 its atlas of beautiful plates forming one of the most remarkable additions 

 to zoological literature. 



Psorosperms.* — Sig. A. Garbini finds that the granulations of the proto- 

 plasm and of the nucleus of Psorosperms found in the caecum of the porpoise 

 are not homogeneous, since by means of his double stain, some colour blue, 

 others red. This difference only exists in the unincapsuled condition ; at 

 other times the granulations stain of one colour either all blue or all red. 

 The author offers two explanations, either that before incapsulation the 

 Psorosperm divides in such a way that all the blue-selecting granulations 

 form one-half, and all the red-selecting the other half, or that during 

 incapsulation the one set of granulations alter so as to become homogeneous 

 with that of the other ; in some cases becoming blue-selecting, in others 

 red-selecting. 



BOTANY. 



A. GENERAL, including the Anatomy and Physiology 



of the Phanerogamia. 



a. Anatomy, f 



CI) Cell-structure and Protoplasm. 



Young Condition of Vacuoles.^— Contrary to the generally accepted 

 view, Herr F. A, F. C. Went has determined the presence of minute 

 vacuoles even in the youngest cells, as, for instance, in the growing point. 

 This was demonstrated by the application of a 10 per cent, solution of 

 potassium nitrate, which kills the outer protoplasm and isolates the vesicles 

 of cell-sap ; they can then be burst by washing with water or by heat, and 

 their fluid contents shown. The author found vacuoles also in oospheres, 

 pollen-grains, and cambium-cells, and believes that they are present in all 

 living cells, except possibly antherozoids, bacteria, and Cyanophyceae. 



Movements and changes take place at a very early period in these 

 vacuoles, and the author believes that they always commence in the very 

 youngest condition of cells, though they do not become readily obvious till 

 a later period ; these movements being always accompanied by changes in 

 the form of the vacuole. Two frequently coalesce into a single vacuole, 

 while others divide repeatedly by constriction through their middle. 

 These processes are well seen in Dematium pullulans, in apical cells, 

 meristem-cells, pollen-grains, and especially in young hairs ; in young 

 hairs of Cucurhita Pepo and in Cladosporium lierharum this division of a 

 vacuole was seen to be followed by cell-division. All the vacuoles in a 

 plant result, according to these observations, from the vacuoles of the 

 oosphere, and these again from those of the mother-plant. Statements by 

 previous observers of the fresh formation of vacuoles under certain circum- 

 stances he believes to be due to erroneous observation. 



The author also calls attention to the occurrence in the same cell of 

 vacuoles with different contents. In coloured cells it is not unfrequent to 



* Ace. Agr. Art. Comm. Verona, Ixiu. (1886). 



+ This subdivision contains (1) Cell-structure and Trotoplasm; (2) Other Cell- 

 contents ; (3) Secretions ; (4) Structure of Tissues ; and (5) Structure of Organs. 

 X Arch. Ne'erland., xxi. (1887) pp. 283-315 (2 pis.). 



