. Science-gossip . ion, boththe new cells had lengthened and curved, so thatthey closely resembled the normal fronds in form,except being a little more slender perhaps (fig. 6),When this alga is actively dividing, several pairsmay sometimes be seen on the same slide which a film of the C/csf^rnoK-bearing detritus, and exam-ining this under a one-inch objective will not failto show some frondsin this state after a few repeti-tions of the examination at the proper lunula is exceedingly common in the largelake in Beech Park, near Hadley, along with , C. lineatuni, etc
. Science-gossip . ion, boththe new cells had lengthened and curved, so thatthey closely resembled the normal fronds in form,except being a little more slender perhaps (fig. 6),When this alga is actively dividing, several pairsmay sometimes be seen on the same slide which a film of the C/csf^rnoK-bearing detritus, and exam-ining this under a one-inch objective will not failto show some frondsin this state after a few repeti-tions of the examination at the proper lunula is exceedingly common in the largelake in Beech Park, near Hadley, along with , C. lineatuni, etc., and many beautifuldiatoms. The membrane of the Closteria is more or lesshorny and often brownish, especially in the oldfronds, and is either smooth or marked with longi-tudinal striae, as in C. strialatum ; this species wasvery abundant in a little pond (or rather, puddle)on Hampstead Heath, known locally as the DuckPond, and also in the Viaduct Pond in the samelocality. 3, Cathcart Hill, London, N.; July, Subdivision of Closterium lunula. Fig. I.—A frond just dividing x 350. a, active, and b, passive cells. Figs. 2-5.—Later stages of same x 200. Fig. 6.—Two perfect fronds x 100. have just completed this metamorphosis. Thetemperature at the time of this observation wasabout 16^ C. The vacuoles at the apices of the cells constantlyalter their places in the hyaline motile protoplasm,and contain watery contents in which the minutecorpuscles rotate. The way they enter the vacuoleis very curious: at first they are seen to ap-proach it and then are passed through its side, inthe same way as the sarcode of the Amoebaencompasses a food particle. But of 321 fronds of Closterium lunula examined inOctober, 1895, there were only seven undergoingthis change, and when we consider that it requiresonly a few hours to complete this division, afterwhich the fronds remain several days, or evenweeks, before they again subdivide, it is not sur-prising that they are not more frequent
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