Starch-Formation in Hydrodictyon 
utriculatum. 
BY 
H. G. TIMBERLAKE, 
Instructor in Botany , University of Wisconsin. 
With Plate XXXIV. 
HILE the subject of starch-formation in the plant-cell 
V V has received a great deal of attention from botanists 
from the microchemical standpoint, very little has been done 
in the way of following, by the aid of suitable technique, the 
sequence of structural changes undergone by the cell in such 
a process. This is particularly true in the case of the green 
Algae where the formation of the starch is connected with 
the pyrenoid. The cells of Hydrodictyon furnish material 
suitable for working out the sequence of events in the manu- 
facture of starch, and I have been able to determine in them 
a number of facts, heretofore undescribed, which help to 
explain some of the conflicting statements of previous in- 
vestigators. 
The observations of Schmitz *, Meyer 2 , and Schimper 3 as 
1 Die Chromatophoren der Algen, 1882 : Beitrage zur Kenntniss der Chromato- 
phoren. Jahrb. f. wiss. Bot., Bd. xv, 1884, p. 1. 
2 Ueber Krystalloide der Trophoplasten und iiber die Chromoplasten der 
Angiospermen. Botanische Zeitung, Bd. xli, 1883, pp. 489, 505, 525. 
3 Ueber die Entwicklung der Chlorophyllkorner und Farbkorper. Bot. Ztg., 
Bd. xli, 1883, pp. 105, 1 21, 137, 153, 809. Untersuchungen iiber die Chloro- 
phyllkorper und die ihnen homologen Gebilde. Jahrb. f. wiss. Bot., Bd. xvi, 
p. 247. 
t Annals of Botany, Vol. XV. No. LX. December, 1901.] 
