CHK.MISTKV or THE YEAST CELL NUCLEUS. 165 



To the re<ic]t*i- the mtuiitioii of nuclt'iii in cfU nuclei genemUy, 

 ami in those of the yeast cell in particular, will not ajjjieai to 

 have been clearly detineil in the f<jrcgoing lines. Thi.s view is 

 correct, liy inacrocheniicjil means it is im}>ossible to arrive at 

 more than a hypothesis jKJs.se.ssinjj a certjiin proliahility, it Wing 

 found that cells or aj^filomej-ations of cells, cont^iining either a 

 large number of nuclei or nuclei of con.sideiiiV»le size, yield a 

 higher j»roiH)rtion of nuclein than such as conUiin only a few 

 nuclei or tho.se of small dimensions This was the conclusion 

 formed l>y Mieschei-, who succeeded in separating the cell nuclei 

 from the pus cells on which liis exhaustive experiments were 

 performed. liy similar companitive methods, A. Kossel (L) 

 came to the conclusit)n that nuclein, instead of being a resei-ve 

 material, plays an active part wherever new cells are in course 

 of formation and nuclear reprmluction is consequently in pi*o- 

 gress, i.e. in all phenomena of germination. Thus the formation 

 of nuclei and nuclein proceeds simultmeou.sly. This opinion 

 was also shared by H. A. Laxdweuk (I.). The sole method of 

 obtiiining reliable information with regard to the .situation of 

 the nuclein within the cell is by microchemieal examination. 

 With this ol>ject use can be made of the high re.sistiince olfered 

 by the nucleins towards pep.sin. For example, E. Zachakias (L) 

 detected the presence of nuclein in the nuclei of pressed yeast 

 cells by the aid of .so-called artificLil ga.stric juice (a .solution of 

 pepsin in 0.2 per cent, hydrochloric acid). The stiiining methotls, 

 howevei*, are caj)able of more extensive ajipliwition. 



The various indiviilual chemical constituents nf the cell ex- 

 hibit divergent absorptive allinities for dilTerent dye.stulTs. It is 

 known that fiom a mixture of red, blue, or green dyestuffs one 

 cell constituent will ab.sorb chiefly or entirely the first-named, 

 ij\ erythrophil, whereas ant)tlier cun.stituent will prefer the Idue 

 (or green), and is therefore termed cyanophil. This preference, 

 however, in each case is determineil, not l)y the .shade of colour, 

 but by the chemical constitution (or reaction) of the dyestuff. on 

 the one hand, and by that of the cell cc»nstituent,s with which it 

 is brought into contact, on the other. A cell con.stituent is 

 therefore .sjiid to be acidophil when, from a mixture of acid and 

 ba.sic dye.stutTs, it absorbs the former and becomes stjiined there- 

 with ; in the conveise case it is termed basophil. Chemical 

 atlinity is almost the sole factor influencing the occurrence or non- 

 occurrence of .st:iining, so that, in presence of a mixture of an acid 

 red dyestulT and a Imsic blue dyestulf, a given ba.sophil cell consti- 

 tuent will behave as a cyanophil, but, in presence of a mixture 

 of a basic red and an aciil blue dyestulT, as an erythrophil. An 

 instance of this kind is alTorded by the nucleic .-kmiI of yea.st, 

 which is strongly basopliil, and. according to ob.servatitms made 

 by H. Malkaiti (L), E. Zachakias (II.), and L. Liliexkeud 

 (I.), is stained (blue or green) by a mixture of Acid Fuchsine 



