POTASH FROM KELP. 3 
color.-and differ but little in appearance from the spores of some 
of the green seaweeds. The diameter varies from about 2 to 6 
‘microns and the length from about 4 to 6 microns; 1n other 
words. it would take 200 or 300, placed end to end, to span a pin- 
head. They vary in form from nearly globular. to slender spindle- 
shaped. The spores borne in the autumn are mostly of the spindle- 
' shaped type, are small, only slightly colored, and ue 
highly motile. The large globular spores appear 
mainly in midwinter. They are deeply colored, 
very sluggish, and soon come to rest. The cilia by 
means of which the spores swim can scarcely be 
distinguished in living spores under the ordinary 
- powers of the microscope, but they are very slender, 
~ and attached either at the apex or on the side of a 
spore. 
PLANTING IN AQUARIA. 
‘ 
| 
Spores have been repeatedly germinated in the 
_ laboratory and the sporelings kept alive for a 
_ period, sometimes of several months. For success- 
- ful germination a cool, well-lighted room is re- 
_ quired. A glass vessel is the best container for the 
culture, on account of its permitting full penetra- 
tion of light. If it is possible, a constant stream of 
| sea water at ocean temperature should be kept run- 
- ning into the vessel, or if there are not the means 
for keeping a stream running, the water should be 
_ changed frequently and, in addition, should be fre- 
_ quently agitated to work in air. With suitable con- 
ditions, sporelings may be had by placing a few 
fresh, mature sporophyls in the culture vessel. 
_ Whether the spores are good or not can quickly be 
4 found out by scraping off a little of the soft tissue 
_ near the tip of a sporophyl and examining it under 
_ the microscope. Healthy spores float out and soon 
may be seen swarming about in a manner resem- 
bling bees. Within an hour after planting the 
_ sporophyls the water takes on a brown color as y 
_ though full of fine mud. This color continues 
for a day or two, but finally the water clears if rie. 1.-Sporophyi. 
there is good circulation. This subsequent clear-  Sh2ded, areas are 
ing is due to many spores coming to rest or at-  “ipe sorus at the 
. ‘ tip, young sorus 
taching themselves to a fixed object. The spores developing’ at the 
~ come to rest sometimes in a few minutes; at other — Dase, and Jensthe 
_ times they may swim for 24 hours. Currents have — stows. One-half 
much more to do with their wide dissemination than >” 
_ has their own motility, but the latter probably enables them to get 
_ out from the shade of the parent plant. 
__ When the spores come to rest they take on a globular form, and 
_ their walls become thick and mucilaginous, enabling them to cling 
_ to the glass walls of the culture vessel or to any other object with 
_ which they may come in contact. If there is no circulation in the 
culture vessel, the spores become the prey of bacteria within two 
