ZOOLOGY AND BOTANY, MICRO SOP Y, ETC. 455 



grown in nitrogen-free media and dried on cotton immersed in the 

 culture. These cultures are sent out by the Department of Agriculture, 

 together with packages of nutrient salts to multiply the organism ; the 

 culture thus obtained is used to inoculate the seed or soil. 



Irritability. 



Immunity of Plants to their own Poison.* — G. J. Stracke, as a 

 result of a number of observations with various herbaceous plants, con- 

 cludes that in some cases the cells of the tissues of the higher plants possess 

 an immunity to their own poison when presented in a chemically pure 

 state, but that this is not a general rule. Moreover, such cells may show 

 immunity to other injurious substances, which may or may not be 

 chemically related to the poison which they themselves contain. Ex- 

 periments made with the liquids expressed from the cells suggest the 

 possibility that these liquids may contain substances which are more 

 injurious to the cells in question than to others. It is perhaps not a 

 matter of indifference for the life of the protoplast that the action of 

 the poison be directed from the vacuole to the external layer of the 

 protoplast. Or it is quite possible that in many cases a cell-fluid, origi- 

 nally innocuous, acquires after its isolation toxic properties as the result 

 of decompositions set up by enzyme action. 



General. 



Experiments on the Attraction of Bees by Flowers.t — Josephine 

 Wery gives an historical account of the work of previous observations on 

 the subject of the attraction of bees by flowers, followed by a descrip- 

 tion of experiments made by herself in two different seasons in the 

 Brussels Botanic G-arden. The author concludes that the brightly 

 coloured parts of the flower are the chief attraction, the honey and 

 the perfume apart from the colour having but very slight attractive 

 power. If the total attractive power of the flower be represented by 

 K>0, the effect of the form and colour will be represented by about 80 

 and that of the other factors — presence of pollen, nectar and perfume, 

 taken together — by about 20. 



Relation between Ants and Plants. $ — E. Ule gives a catalogue of 

 the plants collected by himself in the Amazon region with which ants 

 were found associated. The collection comprised twenty-eight species of 

 ants (determined by Professor A. Forel) and more than thirty associated 

 plants. The plants are included in the following families : Araceas 

 {Anthurium), Brorneliaceae {Tillandsia), Moraceae, Polygonaceaa {Trip- 

 la ris), Leguminosse, EuphorbiaceasOS'^wm), Melastomaceaj, Boraginaceae 

 (Cordia), and Rubiaceas (Duroia). 



Fossil Fruits from the Tertiary Lignites.§ — G-. H. Perkins 

 describes the results of his study of a large collection of fossil fruits 



* Arch. Ne'erland ScL, Ex. and Nat., ser. 2, x. (1905) pp. 8-61. 

 t Bull. CI. Sci. Acad. Roy. Belg., 1904, pp. 1211-61. 

 t Flora, xciv. (1905) pp. 491-7. 



§ Rep. State Geologist Vermont. 1004, pp. 174-212 (7 pis.). See also Bot. Gazetto, 

 xxxix. (1905) p. 371.; 



