104 CARNEGIE INSTITUTION OF WASHINGTON. 



undoubtedly some of Flemniing's Jila, some of van Beneden's micro- 

 somes, von la Valette St. George's cytomicrosomes and "Nebenkern," 

 and most of Altmann's bioblasts, are identical with chondriosomes. 

 The value of the recognition of this fact should not be underestunated, 

 inasmuch as it has brought about a satisfactory simplification. From 

 the same point of view another desirable result is the conciliation 

 between two long-discussed and ardently supported theories of the 

 stnicture of the protoplasm, namely, Flemniing's filar and Altmann's 

 granular theories ; for it has been demonstrated that in many cases both 

 have described the same substance and that this substance may appear 

 in granular as well as in filamentous fonn. 



As happens in every new field, the research work on chondriosomes 

 has passed through a phase which may be properly characterized as 

 the descriptive stage, the stage of pioneering work. At present the 

 tendency is rapidly developing to attack the problem from the experi- 

 mental side, and in this connection should be emphasized the value 

 of the tissue-culture method b}^ means of which many fonner observa- 

 tions have also been confirmed. The experimental methods, chemical 

 research included, should prove very valuable, and should help 

 to solve important problems, for although the importance of the 

 chondriosomes is generally admitted, their role in connection wdth the 

 difTerentiation and the life of the cell is much discussed. Finally, it 

 should be pointed out that in the domain of pathology the cell proto- 

 plasm has hardly been explored in a systematic way and that, for 

 instance, the study of the cytoplasm in tumors might perhaps give 

 results not only interesting but also of some practical value. 



Mrs. Margaret R. Lewis and Dr. R. B. Robertson have applied the 

 method of tissue cultures and vital staining to the study of the mito- 

 chondria in the genn-cells of a grasshopper {Chortippus curtipennis 

 Scudd.) and their results are in agreement with the conclusions drawn 

 by others from the study of teased tissues or of fixed and stained 

 preparations. Mitochondria are found in the primary speimatogonia 

 of Chortippus as small, dehcate granules. They certainly do not arise 

 in the male germ-cell, since they are already present in the earliest 

 genn-cell, and there is no evidence that they are fonned at the expense 

 of any nuclear material. In the prophases of the first division the 

 mitochondria dispose themselves in threads and surround the spindle. 

 This substance is divided into two clumps of about equal size during 

 both spermatocyte divisions. In the spennatid the mitochondria 

 conglomerate into a compact body, the previously so-called "Neben- 

 kern," which divides into two parts and, after undergoing several 

 changes in the structure, finally builds two threads which surround 

 the axial filament extending along the length of the middle piece of the 

 spermatozoon. Besides the mitochondria, these authors found, in all 

 generations of genn-cells, granules that stain vitally with neutral red. 



