524 EXPERIMENT STATION RECORD. 



The relation of parasitic fungi to the contents of the cells of the host 

 plants. — I. The toxicity of tannin, M. T. Cook; and J. J. Taubeniiaus ( Dcla- 

 icarc 8ta. Bui. 91, pp. 3-77, pis. 10).— The authors give the results of experi- 

 ments with certain fungi in which the intlueuce of tauniu on their germination 

 and growth was tested. The fungi were grown in various media to which 

 various percentages of tannin had been added. Three species of Colletotrichum, 

 8 species of Gloeosporium, GlomereUa mfomaculo/m, 12 species of Fusarium, 

 several species of Ceratostomella, Corticium alutaceum, Lentodiuni squamu- 

 losiim, 2 species of Graphlum, 4 species of Cladosporium, Alternaria solani, 

 SphoTopsis malorum, Sclerotinia fructigena, Diaporthe parasitica, Peniophora 

 Candida, 3 species of Penicillium, Neocosiiwspora vasinfecta, Guiffnardia hid- 

 loellii, Septoria verbasicola, Ascochyta pisi, Cephalothecium roseum, some 

 undetermined species of Phyllosticta, Rhizoctonia, and Phoma, Cladosporium 

 macrocarptim, Aspergillus, 3 rusts, and 1 smut were grown on certain media and 

 the results noted. 



It was found that the first action of tannin is to inhibit or check germination 

 and finally to kill the spores. Low percentages of tannin in distilled water may 

 stimulate germination and growth and seem apparently to serve to some extent 

 as a food. As the maximum percentage of tannin in which spores will 

 germinate and grow is approached, the mycelium tends to become short, thick, 

 and very septate. Tannin has a tendency to retard or inhibit the growth of 

 fungi. The parasitic forms are more sensitive to the action of tannin than the 

 saprophytic ones. The majority of the parasitic fungi tested were retarded 

 by from 0.1 to O.G per cent tannin. The fruiting was frequently stimulated by 

 low percentages of tannin. The action of tannin is practically the same 

 whether the organism is grown in agar or in liquid media. 



The origin of the chloroplasts in the cotyledons of Helianthus annuus, 

 E. C. Miller {Bot. Gaz., 51 (1911), No. 5, pp. 378-38/,, pi. i).— After a review 

 of the opinions of various investigators on this subject, the author gives the 

 results of a study of H. annuus seedlings when grown under greenhouse condi- 

 tions at a temperature of from 65 to 75° F. 



From a study of the sections of the seedlings at various stages of growth 

 the conclusion is reached that chloroplasts are present in the resting seed, 

 but are very minute, and that as the seeds germinate these chloroplastids in- 

 crease in size and multiply by simple fission, thereby giving rise to chloroplasts 

 of the mature seedlings. 



Dimorphism of the gametes of CEnothera, H. de Vries (Biol. Centbl., 31 

 {1911), No. //, pp. 97-10},; rev. in Science, n. ser., 33 (1911), No. 858, pp. 897- 

 S99). — In a series of cross-fertilization experiments with certain species of 

 OBnothera the author found that the ovules and pollen grains carry different 

 hereditary tendencies, for in reciprocal crosses with O. Mennis and O. muricata 

 the resulting hybrids were very unlike and strongly patrocline, showing in 

 both instances only slight traces of any influence by the female parent. The 

 common O. Mennis represents the form inherited from the pollen, while the 

 ovule characters are recessive. 



This property of producing gametes having diverse hereditary qualities is 

 termed " heterogamie " by the author. When the reciprocal hybrids of the same 

 2 parents are crossed, the resulting hybrids are called double reciprocal hybrids, 

 in which, if a pati-ocline hybrid is crossed with the pollen of the paternal species, 

 what the author calls iterative hybrids results, exactly like the first hybrid and 

 very like the paternal species. If. on the other hand, a patrocline hybrid is 

 crossed with pollen of the mother species, the resulting hybrids will have the 

 grand-paternal species eliminated, and are called sesqui-reciprocal hybrids. 



