570 SCIENCE PROGRESS 



nucleus. From the time when the young are born, and 

 throughout lactation, the apparatus remains hypertrophic, " in 

 part fragmented and shifted and stretched in various direc- 

 tions. The hypertrophy and partial fragmentation are very 

 likely connected with the activity of the cells ; the shifting 

 and stretching appear chiefly due to the increased intracellular 

 pressure. These facts are against the identification of the 

 apparatus with a fixed system of intra-protoplasmic canaliculi." 

 During the period of involution after lactation when the 

 epithelial cells undergo considerable changes, the apparatus is 

 broken up into a number of pieces of various shapes. Most of 

 these cells are eliminated with their deformed apparatus. 

 Some, however, remain and form the permanent epithelium 

 of the " resting " gland, and Da Fano suggests that the 

 apparatus of such cells is rebuilt from the " fragmented and 

 perhaps fluid materials out of which the old one was formed." 

 Other important papers are : 



Berg, W., " Ueber f unktionelle Leberzellstrukturen II, " Archiv fiir mikroskop. 



Anat., vol. xcvi. No. i, 1922. 

 Bonner, G., " Double Sex-linked Lethals in Drosophila melanogaster ,"" 



Acta Zoologica, i, 1922. 

 BowEN, R. H., "On the Idiosome, Golgi Apparatus, and Acrosome in the 



Male Germ Cells," Anat. Rec, vol. xxiv. No. 3, Oct. 1922— a survey 



and synthesis of recent researches. 

 GuTHERZ, S., " Das Heterochromosomen- Problem bei den Vertebraten," 



Part II — " Untersuchung der Spermiogenese der weissen Maus," Archiv 



fiir mikroskop. Anat., vol. xcvi. No. i, 1922. 

 Voss, H., " Der mikrochemische Nachweis oxydativer Fermente in den 



Spermien des Menschen," Archiv. fur mikroskop. Anat., vol. xcvi, No. i, 



1922. 



Histology, — ^The second part of O. Van der Stricht's " fitude 

 de la Retine par I'ancienne methode d 'impregnation au nitrate 

 d'argent " (Archiv de Biol., vol. xxxii. No. 3) is devoted to 

 an account of the application of this method to the study of 

 the radial fibres of Miiller and the external limiting membrane 

 of the retina, and emphasises the value of this method in the 

 investigation of these structures. 



A study of the lymph nodes of the common wild rat has 

 shown that there are two structural types. Either the nodular 

 part of the gland surrounds the sinusoidal portion, except at 

 the hilus, or the nodular and sinusoidal portions are lodged at 

 opposite ends of the node. Accessory nodes, which are the 

 result of some special stimulus, are always of the former type 

 ("Studies on Lymph Nodes" — (i) Structure: Introductory 

 paper, by T. T. Job. Am. Jour, of Anat., vol. xxxi. No. 2, 

 Nov. 1922). 



C. C. Macklin has dissected from the fresh trachea and 

 larger bronchi of the mammalian lung, the entire elastic mem- 



