PHAEOPHYCEAE 
203 
Hole, Massachusetts (George M. Gray), for living material. Fertili¬ 
zation occurs at all seasons, but autumn is the most favorable. In 
summer the material dies before it reaches Chicago, but during the 
rest of the year a pailful will reach Chicago, and even as far west as 
the Mississippi River, in good condition for showing the rotation 
of the egg by the sperms. The eggs and sperms form slimy masses, 
the antheridia being orange red, and that containing the eggs a dirty 
green. Mix a drop of the red with a drop of the green. The move¬ 
ments of the egg can be observed, and material for a study of fertili¬ 
zation and later stages is easily secured. In fixing fertilization 
and succeeding stages, it is worth while to use some of the regular 
Fig. 50. —Dictyota dichotoma: longitudinal section through apical region showing two apical 
cells, the one on the right dividing again to produce another dichotomy. Stained in iron-alum 
haematoxylin. Photomicrograph by Miss Ethel Thomas. X167. 
Flemming's weaker solution, as well as the solution without the 
osmic acid. 
For the growing points and conceptacles, small pieces should be 
cut off with a razor. If the fruiting tips be cut through lengthwise 
before they are cut off, the fixing will be more satisfactory. For 
sections of the conceptacles it is better not to cut across the whole 
tip, but to cut off pieces of the rind containing half-a-dozen concep¬ 
tacles. Such pieces are more easily imbedded and cut. There is no 
difficulty in cutting such pieces in paraffin. Iron-haematoxylin is a 
good stain. Safranin and gentian-violet are also satisfactory, but 
care must be taken not to overstain since Fucus usually stains deeply 
and rapidly. 
For the cytologist, Fucus might be used as a test object for testing 
proficiency in technic, just as Pleurosigiua angulatuTn is used in test¬ 
ing an objective. The nuclear divisions in the antheridium are 
