ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 61i 



Henri van Heurck.* — J. Chalon publishes an obituary notice of 

 the late Professor H. van Heurck, who died last March at Antwerp, 

 aged 71 years. He gives an account of his collections of drugs, 

 Microscopes, diatoms, algae, phanerogams, physical instruments, etc. 

 One of the unique treasures is Moller's famous type-slide containing 

 4026 species of diatoms arranged in perfect order within a square of 

 6 mm. diameter. It cost 40Z.; and it occupied Moller forty full days 

 to place the diatoms in position. From 1864-99 van Heurck was 

 Professor of Chemistry at the School of Industry at Antwerp. Placed 

 in charge of his father's factory of paints and varnishes, he invented 

 certain varnishes and lacquers which have stood the lapse of time 

 remarkably well. He prepared and patented the dentifrice Odol. In 

 1876 he was appointed professor for life at the Antwerp Botanic 

 Garden. A long list of his publications is given. The proofs of his 

 last work — on the Diatoms collected by the ' Belgica ' Antarctic 

 Expedition — he finished correcting on his death-bed. 



Fungi. 



(By A. Lorrain Smith, F.L.S.) 



Chrysophlyctis endobioticaj — T. Johnson and F. Weiss have pub- 

 lished an account of the germination of the so-called spores of Chryso- 

 phlyctis in successive papers. The spores germinated in potato-juice, 

 and proved to be zoosporangia full of zoospores, seen in active motion 

 before escaping through a slit in the wall of the sporangium. Weiss adds 

 that the zoospore stage is followed by an amoeboid stage. Finally, the 

 pseudopodia are withdrawn, and the organism comes to rest, taking a 

 spherical form. 



Chrysophlyctis endobiotica and other Chytridiacese.f — T. Johnson 

 has followed the germination of the resting sporangium or " spore " of 

 Chrysophlyctis, the walls of which split, allowing the escape of the 

 zoospores. A new infection takes place by the penetration of these 

 zoospores from the soil or by the internal passage of plasmodium from 

 diseased tubers used as seed to the new tubers. Notes are also given on 

 Uropldyctis leproides, a disease of the beet, and on Asterocystis radicis, 

 which attacks the root-hairs and roots of flax plants. It also occurs on 

 the roots of grasses and of weeds in the flax-field. A number of Chy- 

 tridiaceae live on algae, and are briefly commented on by the author. 



Notes on Mucor.§ — L. Raybaud has been experimenting on Mucor, 

 to test the influence of osmosis and of transpiration on the morphology of 

 the organs. On juice of orange, and in damp conditions, when more 

 moisture was supplied the mycelium increased its dimensions, and finally 

 burst, with the escape of the protoplasmic contents ; when it did not 

 burst, swellings were formed on the hyphaa and the formation of spor- 

 angia was arrested. 



In the case of accelerated transpiration, a current is set up towards 



* Bull. Soc. Roy. Bot. Belg., xlvi. (1909) 31 pp. (3 pis.), 

 t Nature, lxxix. (1908) pp. 67 and 98. 

 X Proc. Roy. Dublin Soc, xii. (1909) pp. 131-44 (3 pis.). 

 § C.R. Soc. Biol. Paris, lxvi. (1909) pp. 1118-21. 



