16 SUMMARY OF CURRENT RESEARCHES RELATING TO 



understanding certain questions at issue between himself and 

 Flemming. More recently, as Flemming shows, Peremeschko appears 

 to Lave made two very interesting discoveries. He has seen the 

 division of nerve-nuclei, and has also observed the indirect division of 

 white blood-corpuscles. It would now seem that Schleicher (p. 175) 

 has abandoned the points of difference (here concisely summed up by 

 Flemming) between these two investigators. Flemming dwells at 

 much length (pp. 176-184) on the many details, trifling as well as 

 important, wherein he and Strasburger differ. These we cannot now 

 notice. Strasburger and Flemming, nevertheless, essentially agree 

 touching the probability of one general law of cell-development for 

 all animal and vegetable structures. 



A third Part is promised in continuation of the present, with an 

 account of the development of the ovarian egg, and references to a 

 valuable paper by Arnold on the cells of tumours.* Already (p. 245) 

 the author comj)ares cell-division to a process of asexual propagation, 

 and uses the researches of Mayzel and Eberth on cell-development in 

 pathological subjects (chiefly the inflamed cornea of the rabbit). 



It is scarcely possible to epitomize this long paper, which is at 

 once critical and original, descriptive and speculative, which comes 

 in the middle of a series of current investigations, contains a revision 

 and extension of previous researches, and abounds in necessary 

 repetitions and digressions. Flemming's merits are manifest, both as 

 a critic and independent investigator. On so far-reaching a topic, 

 aftecting almost every department of living natui'e, his work well 

 deserves to be studied in extenso with the same carefulness which 

 has guided its preparation. 



Formation of Epithelial Cells andNuclei-t — Flemming criticizes 

 an essay by Dr. Otto Drasch,J on the physiological regeneration of 

 the ciliate epithelium of the trachea, and takes this opportunity of 

 showing how so intelligent and praiseworthy an observer has been 

 led astray in his efforts to re-establish erroneous opinions touching 

 the free-formation of nuclei. Flemming further points out how effects 

 due to reagents had in like manner previously deceived both Lott 

 and W. Krause. With Klein and Strasburger, he is prepared to 

 maintain the doctrine — omnis nucleus e nucleo, — until the contrary has 

 been expressly demonstrated, and lays just stress on Strasburger's 

 brilliant rejection of the occurrence of " free cell-formation " in the 

 embryo-sacs of phfenogams, an expose which tends strongly to support 

 the belief in one general law of division for all nuclei. 



Gastric Epitlielium.§ — Dr. E. N. v. Eegeczy gives a woodcut and 

 description of ciliated cells from the frog's stomach, which resemble 

 the characteristic cells of the duodenum. 



Cells of Spinal Ganglia. || — Dr. B. Eawitz recapitulates some of 

 his predecessors' studies of spinal ganglia, and dwells on. the danger of 



* Virchow's Archiv, Ixxviii. 



t Arcli. Mikr. Anat,, xviii. (1880) pp. 347-364. J Wicn. Sitzb., Oct. 1879. 



§ Arch. Mikr. Anat.. xviii (1880) pp. 408-11 (1 fig.). 



II Ibid., pp. 283-301 (1 pi.). 



