324 



Journal of Applied Microscopy. 



colur is likely to fade after two or three 

 months, though it may remain for a 

 much longer time. For studying the pre- 

 parations to the best advantage two 

 millimeters apochromatic homogeneous 

 immersion objectives and the appropriate 

 compensating oculars are needed. 



Employing this method, the authors 

 have studied the nucleus and cytoplasm 

 of yeast cells, the process of budding and 

 the accompanying karyokinetic changes, 

 and the formation of spores. The inves- 

 tigations were evidently carried on in the 

 most careful manner, and the results 

 obtained seem entirely trustworthy. Of 

 the many conclusions arrived at, the fol- 

 lowing are the most important: 



1. Every yeast cell in the quiescent 

 state encloses a nucleus. 



2. This nucleus consists of a mem- 

 brane, caryoplasm, and nucleolus. 



3. In well nourished yeast cells the 

 cytoplasm has a typical reticulated struc- 

 ture and a nucleus as indicated above. 



4. In the budding of Saccharomyces 

 Ludwigii, tke nucleus undergoes a very 

 reduced indirect division. The spindle 

 is plainly visible as well as the cell plate. 



5. In Saccharomyces cerevisiae the 

 division of the nucleus is made in the 

 direct manner at the tinre of budding. 



6. In this species at the same time the 

 nucleolus divides into two in the mother 

 cell in the neighborhood of the bud. One 

 of the nucleoli then passes into the bud 

 by the pedicel, which separates the bud 

 from the mother cell. 



7. In cells which are preparing to form 

 spores two nuclei appear. These fuse 

 and the resulting nucleus contains double 

 the amount of nucleine found in an ordi- 

 nary nucleus. Thus a fecundated egg 

 results. 



8. The new nucleus divides by a sort of 

 very reduced kinesis, a spindle, fusorial 

 plate, and cellular plate being evident. 



9. A second division follows, accom- 

 panied by the same figures, though more 

 reduced. 



10. Thus, four nucleoli are produced. 

 Around each of these and the contiguous 

 cytoplasm a membrane forms and the 

 nucleus of each spore is thus reconsti- 

 tuted. 



The paper contains numerous valuable 

 criticisms of the methods and results of 

 Schmitz, Hansen, Dangean^ Moeller, and 

 other students of the yeasts. The plates 

 Include more than two hundred figures. 

 Charles Wright Dodge. 



Recherches cytologlques sur la cellule 

 de levure, par MM. Fr. A. Jenssens et A. 

 Leblanco. Annales de Micrographie Nos. 

 4 et 5. Avril et Mai, 1898, pp. 113-151, 2 

 Planches. 



ness, the scientific programme was 

 opened by Dr. Bremer, a resume of whose 

 paper follows: 



Dr. Bremer demonstrated crystalloids 

 in diabetic and leukemic blood. Crystal- 

 loids can be demonstrated in normal as 

 weil as diseased blood, principally by 

 means of Aethylene blue. In diabetes, 

 especially in the juvenile form, there axe, 

 in the plasma, copious refractive bodies, 

 reminding one, so far as their form is 

 concerned, of bacteria. They are, how- 

 ever, easily distinguished from micro- 

 organisms by their refractive index and 

 their behavior towards the basic anilin 

 dyes. In the dried and unstained speci- 

 men, they give, owing to their great num- 

 ber, a characteristic appearance to the 

 blood film, when examined with a low 

 power (x 150). The blood loolcs "infect- 

 ed," as it were. The greater or lesser 

 masses of these crystalloids seem to be 

 proportionate to the gravity of the dis- 

 ease. Their increase suggests approach- 

 ing coma. From the morphologic appear- 

 ance alone, a diagnosis may be made. 



In leukemic blood, large globular crys- 

 tals are found which are of differentially 

 diagnostic import. Neither in diabetes 

 nor in leukemia is there fat to be found, 

 as has often been asserted. Certainly the 

 bodies demonstrated cannot be regarded 

 as fat, since ether and alcohol do not dis- 

 solve them. A more extensive article on 

 this subject is being prepared by Dr. 

 Bremer. 



The better makes of wooden slide boxes 

 all have a groove in the middle of each 

 end, in order that the slide nearest the 

 end wall may be taken out more readily. 

 It is surprising that the groove is always 

 cut in the middle, for if one takes hold 

 of the slide here the cover glass is 

 usually soiled, or if the balsam is not 

 thoroughly dry the preparation may be 

 injured, especially in the case of large 

 rectangular cover glasses. A groove at 

 the middle is of no use whatever. The 

 slide should be handled only at the ends 

 and the groove should therefore be cut 

 on one side; or better still, two grooves 

 should be cut in each end, one on each 

 side. If this is done, all diflficulty 

 experienced in removing the slides next 

 the end walls will be entirely obviated. 



J. H. S. 



Botanical Laboratory, Ohio State Uni- 

 versity, Columbus, Ohio. 



The St. Liouis Microscopical Society met 

 November 10th, and, after regular busi- 



The curriculum in the Pharmaceutical 

 department of Howard University, 

 Washington, D. C, has been extended 

 so as to include a special course in mi- 

 croscopy and bacteriology. The course 

 will be under the personal direction of 

 Prof. W. W. Alleger. . 



