ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 473 



nuclear substance is suflScient for the formation of a complete nucleus 

 is certain ; it appears, however, that cell-protoplasm can only produce 

 its like and never nuclear protoplasm. 



Dr. Gruber also found that if the divided parts of a Stenfor were not 

 completely separated, they generally tore themselves apart, sometimes 

 by rotating in opposite directions. If the cut was not very deep, 

 monstrous forms might be produced, as for instance with two com- 

 plete anterior or two posterior portions. If an incision is made so 

 as to leave a bridge uniting the two parts the same phenomenon is 

 seen as in animals which are about to divide spontaneously, the 

 movements of the anterior and posterior halves being in accord so 

 long as even only a thread of protoplasm unites them. 



The Stentors are specially suitable for these experiments, on 

 account of their large size, and the clearness with which the synchro- 

 nous movements of the large peristomial cilia on the divided portions 

 can be observed. 



" If," says Dr. Gruber, " a narrow, even thre:.d-like connection is 

 sufficient for the loosely connected pieces to act as one physiological 

 individual, it proves that the nervous conditions are not restricted to 

 definite paths, but that spontaneity governs every protoplasm-element 

 equally. There can be no definite central organ, but each portion of 

 protoplasm is central organ and conductor in one, i. e. the nervous 

 power in the substance of the cell is diffused. It is thus com- 

 prehensible that, for instance, a Volvox- colon j, where the numerous 

 individuals are united by bridges of protoplasm, can behave in their 

 movements as a single individual, swimming backwards or forwards as 

 required, revolving, stopping, and so on. I am convinced that here 

 these bridges serve more for the establishment of a nervous unity 

 than for the mutual nourishment of the separate organisms." 



Gruber's experiments on healing agree with and confirm those of 

 Nussbaum ; but he cannot accept his conclusions, even though unable 

 to offer any suggestion in their stead. 



BOTANY. 



A. G-ENERAL, including the Anatomy and Physiology 

 of tlie Phanerogamia. 



a. Anatomy.* 



Contiimity of Protoplasm.f — Dr. E. Tangl describes observations 

 on this subject made on the bud-scales of the onion, by preparations 

 in sulphuric acid, using soluble anilin-blue as the staining reagent. 



The transverse and lateral avails of the epidermal cells of both 

 outer and inner side of older scales are evidently pitted even when not 



* This subdivision contains (1) Cell-structure and Protoplasm (including the 

 Nucleus and Cell-division) ; (2) Other Cell-contents (including tlie Cell-sap and 

 Chlorophyll); (3) Secretions; (4) Structure of Tissues; and (5) Structure of 



^ans. 



t SB. K.K. Akad. Wiss. Wien, xc. (1884) pp. 10-38. 



