95 



The table shows clearly that as the yeast cells increased in number the quan- 

 tity of alcohol also increased in a nearly corresponding degree, so that, taking the 

 results at the end of twenty-four hours, there is a direct ratio between the two. 

 During the first twelve hours this does not hold good, as during approximately 

 that period there is a large growth of yeast, but no apparent fermentation, as is 

 evidenced by the lack of gas given ofT. For this reason the time between the 

 "pitching," or inoculation of the wort, and the beginning of active fermentation 

 is called the "incubation" period. 



Thanks are due to Mr. W. H. Test for assistance rendered in the work. 



The Circui.ation of Protoplasm in the MANrBRiuM of Chara — Chara 

 Fra<;ilis. By D. "W. Dennis. 



About the middle of May last Mr. Omer Davis, a student in the Biological 

 Laboratory, at Earlham, while studying the fertilization of Chara JVagilis noticed 

 that the nucleus of the manubrium traveled rapidly around the periphery of the 

 cell, with the circulating protoplasm. The phenomenon was subsequently noticed 

 by all the members of a class of eighteen, and the attention of many other persons 

 was called to it, some of whom were familiar with many of the phenomena of 

 moving protoplasm in the leaves of Chara, the stamen hairs of Tradescantia and 

 in other stock illustrations, it astonished all alike. The circuits of the nucleus 

 were timed by Mr. Davis and myself, and found to range from 15, when the 

 phenomenon was first noticed, to 26, something like a half hour later in a minute. 



The circuit of this pai-ticular cell w&s not measured, but a measurement of a 

 large number of cells later convinces me that it could not have been less than 

 five-eighteenths of a mm. This gives a rate of 7.2 millimeters in a minute, or more 

 than four times as fast as the fastest rate given in Goodale's Physiological Botany 

 for protoplasm in a closed cell. I reported these facts to Prof. Barnes, who said 

 they were, so far as he could learn, entirely new, and he asked me to prepare the 

 matter for publication in the " Botanical Gazette." Early ni June I began what I 

 hoped to make an exhaustive study of the phenomenon for this purpose, but 

 could not find a single case in which the motion was going forward. Disintegra- 

 tion had taken place in most of the cells, and in all the motion had stopped. The 

 phenomenon seems, therefore, to be one connected with the growth and matura- 

 tion of the cell in which it occurs. All I can say is that next May we shall per- 

 mit nothing to interfere with the most exhaustive study we can give to the 



