Algae. — Fungi, Bacteria und Pathologie. 177 



which time it slows off and ceases finally aboiit the middle or 

 end of November. The antheridia and oogonia are produced 

 in fortnightly crops which synchronize witii the spring tides, 

 and the development of the crops is determined by the time 

 and height of these tides, progress being very slow during the 

 neaps. The author has watched the development of D. dichotoma 

 both in the Menai straits and at Plymouth and he finds 

 that the difference between the details of periodicity at these two 

 places is due to the difference in the time of day at which 

 low water of spring tides occurs in the two places. In the 

 Menai straits this takes place in daylight, morning and evening; 

 while at Plymouth it occurs at midday and midnight and 

 the consequent loss of illumination causes the Plymouth 

 plants to be poorer^ as weil as several tides later in their de- 

 velopment. Thus periodicity is seen to be actively influ- 

 enced by the amount of light received by the plant during the 

 low spring tides. Other causes may affect the times of Initiation 

 and liberation. such as wind, or a rise of six or seven inches 

 in the tide as the result of meteorological phenomena. 



A study of herbarium specimens shows that periodicity in 

 the case of D. dichotoma obtains in other localities extending 

 to Australasia; but there is no evidence of periodicity oc- 

 curing where there are no appreciable tides. Tetrasporic plants 

 shew no trace of periodicity. 



The author describes the conditions most favourable for 

 the production of regulär crops of gametes and the effect on 

 plants where these conditions are not fuifilled. 



Haliseris seems to have a similar periodicity in the deve- 

 lopment of the sexual cells, but the details of the process have 

 not as yet been fully worked out. E. S. Gepp-Barton. 



Butler, E, S., Some Indian Forest Fungi. Part I. (The 

 Indian Forester. Vol. XXXI. Sept. 1905. '^p. 487—496.) 



Part I. Describes a Casuarlna disease caused by a species of 

 Trichosporium. The fungiis is found in the collar oJ the tree, from 

 whence its spreads to a slight extent in an upward and downward di- 

 rection. The hyphae occiipy the centre of the wood and lie within tlie 

 vessels and cells, boring their way through any intervening cell-walls. 

 The destruction of the wood is not great but the tree ultimately suc- 

 cumbs. At a later stage the fungus fruits abundantly and ruptures the 

 bark. The latter is lifted from the cambium along the trunk into large 

 blisters by the formation of a layer of densely woven hyphae. 



The fungus is named Trichosporium vesiculosiim Butler, spores 

 5—8 X 4—6. A. D. Cotton (Kew). 



COSTANTIN e t LUCET, Recherches sur quelques Aspergillus 

 pathogenes. (Ann. Sc. natur. Botanique. 9*^ sdrie. T. IL 

 1905. p. 119—171. pl. V.) 



Le genre Aspergillus est mainteuu dans ses anciennes limites. les 

 ramifications accidenteües des pedicelles sporiferes ne pouvant preter ä 

 confusion avec leur ramification reguliere et habituelle teile qu'on 

 l'observe dans le genre Sterigmatocystis. Les caracteres des peritheces, 



Botan. Centralbl. Band 101. 1006. 12 



