and Laboratory Methods. 1383 



on the slide is spread by the shaft of the needle in a broad, even streak, a little 

 time being allowed for the drop to run along the needle by capillarity. The 

 most perfect films are thus obtained. The slides are then placed in absolute 

 alcohol for 5 minutes, after which the films are stained with saturated alcoholic 

 solution of haematein. To every 10 c. c. of this solution is added 50 c. c. of alum 

 solution (alum 50 grams, water 1000 c. c). In this solution the slides are left 

 5 to '20 minutes or even hours. Oil is applied directly to the slide without a cover 

 and the specimen examined. A permanent mount can be made by washing off 

 the oil with xylol and mounting the preparation in balsam. If placed in a clean 

 box and wrapped in paper, the slides will keep a year unmounted. a. m. c. 



Qurwitsch, A. Die Vorstufen der Flimmer- ^^ the eighteenth number of this peri- 

 zellen unci ihre Beziehungen zu Schleimzel- odical a work on M. Heidenhain 



len. Anat. Anz. 19: 44-48, looi. j u- u • ^ -^ 



^ appeared which gives an opportunity 



for a few remarks. Heidenhain's work came to the author so shortly before the 



appearance of his previous communication on this subject that it was impossible 



to discuss in the same issue Heidenhain's opinions of the author's statements. 



These are here set forth. The peculiarly shaped epithelial cells in the mouth and 



pharynx of salamander larvae is the subject under special discussion. 



The author has presented, beginning with the earliest stages, the develop- 

 ment and its modifications of the peculiar superficial border of the cells ; first 

 appearing as an apparently homogeneous " crest " not sharply separated, the 

 cell border is next clearly foam-like ; in the course of the further development 

 the foam-like structure is efifaced to make a " felt work." (Arch. f. Mikros. 

 Anat. 57: 209, Fig. 16-18.) 



As an end product of development there comes a clearly formed, sharply 

 isolated border of small rods, of which the separate little hairs correspond in 

 their height exactly to the cilia of the mature ciliated cells and provisionally 

 remain covered with a thin but very sharply apparent, net-like film. At this 

 stage of development direct observation ceased, as the oldest of the remaining 

 larvae showed no more continuance of the process. Based on this observation 

 the author felt drawn to the conclusion that these cells possessed of rods were 

 the early stages of ciliated cells, and also to infer that in one kind of cells at 

 least the cilia are formed before the basal bodies. 



This interpretation of these questioned cells is now doubted by M. Heiden- 

 hain. He regrets that the " last step of development, the peculiar transforma- 

 tion into the true, mature, free cilia, was not observed." The reason for this 

 deficiency was given thus : " I sought to remedy the lack somewhat by figuring 

 in my detailed work (Fig. 21) a mature ciliated epithelial cell next to two inter- 

 mediate ones from the transition of esophagus to pharynx." Heidenhain is much 

 more disposed to consider the pharyngeal cells as forerunners of mucous cells. 

 It seems that a misunderstanding arises each time. Although in both articles 

 the authors speak only of pharyngeal, not of esophageal cells, and although Heid- 

 enhain mentions each time that the pharyngeal epithelium of the salamander 

 was the object treated of, he suggests as a possible cause for confusion on 



