SCIENTIFIC SUMMAET. 
653 
Zoospores, and whose developmental stages are regarded as quiescent ; yet 
here tlie protoplasmic mass, wonderful as it may appear, actually comes 
forth into freedom through an opening considerably smaller than even the 
smallest diameter of the former. This paradox is solved by witnessing the 
phenomenon. A sort of pseudopodal process is protruded through the open- 
ing ; a portion of the contents is slowly drawn after, thus relieving the mass 
behind, which contracts upon itself ; and the gradual expansion and extension 
of the portion outside the old membrane draws with it the whole, and its 
purpose, whatever it may be, is gained. “ What immediately becomes of the 
‘ chlorophyll plate ’ in this process I cannot say, but the whole contents become 
more granular, in which I suppose the ‘plate’ likewise takes apart ; or possibly 
it becomes consolidated in the centre, causing the dark central spot in the 
spore-like body formed by the emerged contents. It^at all events affords no 
obstacle to a process which at first sight, and until it is properly considered, 
appears almost like a feat of legerdemain.” 
Potamogeton nitens in the river Tay. — Mr. John Sim, of Perth, has found 
the longer form of the plant in the latter locality. The lowness of the water 
has allowed him to have access to it for the first time, and as he could not 
determine the name of the plant from want of access to books, he sent a 
specimen to Mr. Babington, who states that it very closely resembles the P. 
anceolatus of Eeichenbach. Mr. Sim alleges that the plant grows in deep and 
very rapid water, in company with P. perfoliatus and P. crispus. — See 
Journal of Botany, August. 
The Staminal Arrangements of the Posacece. — One of the most important 
and philosophic botanical papers which have appeared during the past 
quarter is that by Dr. Alexander Dickson, upon the Morphological 
constitution of the Andrcecium of Mentzelia, and its analogy with that of 
certain Rosacece. In this paper the writer reviews his subject carefully, and 
having discussed the relations of Mentzelia to the Bose family, he proceeds 
to give a classification of the latter, founded on the arrangement of the 
stamens. This may be tabulated in the following manner : — 
I. Alchemilla type. — Single whorl of stamens alternate with the sepals. 
No true corolla. 
{a) Stamens single, e.g., Alchemilla. 
(h) Stamens compound, confluent with petaloid apices, e.g., Ruhus, 
Rosa, Geum, Fragaria, Spircea, &c. 
II. Aremonia type. — Single whorl of stamens sup>erposed to the sepals 
With or without a true corolla. 
(1) With a true corolla. 
{a) Stamens simple, e.g., Aremonia. 
(b) Stamens compound, e.g., Agrimonia. 
(2) Corolla absent. 
(c) Stamens simple, e.g., Sanguisorha. 
(d) Stamens compound, confluent, e.g., Poterium. 
Journal of Botany, July. 
Venezuelan Medicinal Plants. — The following uses of certain Venezuelan 
plants are given by Mr. A. Ernst : — Coco {Cocos nucifera) is cultivated in 
cocoa estates on the sea-shore, and very abundantly about the Lake of 
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