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New Zealand Herald, Volume XXV, Issue 9095, 2 July 1888, Page 6

Nature says that the resistance of pollen to various external influences is the subject of a recent inaugural dissertation by Herr Rittinghans. As to temperature, he found most pollen able to bear 90° C. half an hour, without losing the power of germination. A temperature-maxmnnu was reached at 104'"5 for ten minutes. In conditions favouring germination, pollen does not bear such high temperatures as in the air-dry state. A moderately raised temperature (32* C.) accelerates growth of the pollen tubes. Low temperatures {e.g., under 9) prevent germination, though a cooling to 20" for forty minutes can be borne without injury. As to liquid chemical reagents, the plasma of pollen proved very sensitive to antiseptics (more so, as a rule, than microorganisms), but the resisting power is pretty different in different sorts of pollen. Chloroform vapour acting for twenty minutes was fatal, bromine vapour in five minutes, ammoniacal vapour in ten to twenty minutes. Rotation, several hours, of a spherical vessel holding pollen with nutritive solution, did not prevent free germination. The retention of the power varies widely in different plants. Thus, cyclamen lost it soonest, in seventeen days ; while clivia and a narcissus still had it on the sixty-sixth day: in paeon iu fifty-eight, camellia fiftyone, azalea forty-two. The avorage is thirty to forty days.

Coal-tar on footpaths is recommended a? a preventative of fever by the Medical Officer of Health. (See report to City Council of Auckland 15& iUm;b last.) Those mothers who succeed in getting the footpaths and yards about the house covered with coal-tar will rejoice when the wet weather comes.

LirxtnuA>T Glossy Hair.—To obtain this avoid poisonous hair restorers and dyes, arid use Rowlands' Macassar On., known for nearly 100 years as the best preserver, strengthened and licautifler of the hair. Sold also in a golden colour for fair haired ladies and children. ROWLANDS' Kai4P>ou removes freckles, tan, cutaneous eruptions .mil produces a beautiful complexion. Ask dealers in perfumery for iIov.UL.NDS' articles, of 20, Hatton Garden, London.