DR. MINKS ON THE MICROGONIDIA OF LICHENS. 
37 
The raecaspore of the lichen is without doubt a gonidial organ 
proceeding from the gonohypheme which can be seen at a glance 
from my drawings, and especially in the fresh living spores of 
Septogium, which resemble, to describe them briefly, a little 
colony of Nostoc. Besides, it may be seen that the mecaspore is 
only the product of free intercellular formation ; for the micro- 
gonidia contained in all the cells of the fructifying parts are equally 
here in morpheological activity, from the commencement to the 
end. These phenomena sufficiently prove that the meci and 
paraphyses bear to each other the relation of fertile to sterile 
hyphse. 
It is almost impossible, without the aid of figures (which are not 
given in the Revue ), to convey an adequate notion of Dr. Minks’s 
theories, and we much doubt whether we have caught the exact 
meaning of the author, owing in some measure to the fact that he 
is not writing in his native language, but more especially on 
account of his views being quite novel, and subversive of our 
preconceived notions of the morphology and physiology of lichens. 
(Translated and abstracted by W. Phillips, F.L.S., from Revue Mycolo- 
giquej. 
PREPARATION OF GREEN ALG^. 
By Prof. 0. Nordstedt.* 
Last summer I collected at Jdnkoping the rare and in many 
respects interesting alga ( Sphceroplcea annulina). This alga has 
the chlorophyl in the sterile cellules arranged in transversal bands 
or rings. As I tried to dry them, I found that the rings were 
destroyed by getting dry. I repeatedly tried to get good micro- 
scopical preparations by using liquor Hantzschise” as well as 
acetate of potassium, but when without success I applied warmth. I 
put a small bottle containing the alga in water on a black object, and 
exposed it to strong sunlight for a couple of hours. When the 
alga afterwards was dried, the rings proved to be pretty well pre- 
served ; when afterwards heated by a spirit lamp, the thermometer 
indicated that the rings when boiled — 
minute at 35-40° Cels. | 
When boiled 5-10 minutes at 45°") 
Cels. minute at 50°-98° ,, | 
Did not keep, or were very 
ill-preserved. 
The rings kept very well. 
10 minutes at 60° Cels. 
2 minutes at 98°f ,, 
The rings were separated from 
(• the membrane and placed in 
j the centre alongside the cellule. 
* Translated from ‘‘ Botanische Notisei',” by Dr. S. Berggren. 
t To more than 98° Cels. I could not manage the thermometer to rise. 
