March 6, 1896.] 



SCIENCE. 



347 



are separated under the stimulus of the 

 wound. 7 and 8. Inflorescences showing 

 both fusion and fasciation as when the Ash 

 is attacked by Phytoptus. 



The list of papers upon galls is a long 

 one, including such names as De Lacaze- 

 Duthiers, Prillieux, Courchet, Wakker, 

 Fenzling, Frank, Massalongo, Sorauer, 

 Frauenfeld, Loew, Kieifer, Rubsaamen, 

 Schlechtendahl, Delpino, Thomas, ]S!"alepa, 

 Giard, Julin, Van Tubeuf, Magnus, 

 Schroeter, Peyritsch and many others. A 

 recent writer, Molliard,* has brought 

 together in a systematic way the important 

 facts concerning anthocecidia, and has in 

 several instances added materially to our 

 knowledge of the intimate changes effected 

 in flowers by gall producers. The following 

 is a brief resume of his paper. 



Molliard classifies anthocecidia as fol- 

 lows: 



I. Phytocecidia: Galls produced by plants. 



1. Peronospora galls: Produced by mildews. 



2. Uredineous galls: Produced by rusts. 



3. Ustilagineous galls: Produced by smuts. 



II. Zoocecidia: Galls produced by animals. 



1. Hemiptera galls: Produced by Aphides. 



2. Diptera galls: Produced by flies. 



3. Phytoptus galls: Produced by mites. 



The galls produced in flowers of Dipsa- 

 cus pilosus by Peronospora violacea show 

 that (1) the pollen-sacs have been atrophied 

 and the pollen mother-cells converted into 

 parenchyma; (2) the embryo sac has been 

 atrophied; (3) the sepals have been hyper- 

 trophied. 



Knautia arvensis, attacked by the same 

 mildew, shows (1) atrophy of the stamens, 

 due to indirect influence, however, for the 

 mycelium does not penetrate them ; (2) 

 atrophy of the ovules, also indirectly pro- 

 duced; (3) metamorphosis and hypertrophy 

 of the corolla; (4) incomplete metamorpho- 

 sis of the stamens into petals. 



Matricaria inodora attacked by Perono- 

 spora radii shows (1) coalescences (fusions) 



*Ami. Soi. Nat. Bot. VIII., 1: 67-245. 1895. 



of pedicels and flower tubes; (2) torsion 

 of the flower pedicels resulting from a 

 secondary tissue which reacts against the 

 mycelium ; (3) atrophy of the sexual or- 

 gans; (4) metamorphosis of ligulate into 

 tubular flowers and antholysis of the pistil. 

 Molliard defines three types of Perono- 

 spora cecidiogenic effects : 



1. The flower is not modified. Example, P. calo- 

 theca De By on Sherardia. 



2. The flower is suppressed. Example, P. arbo- 

 rescens on Papaver. 



3. The flower is metamorphosed and its essential 

 functions inhibited. Example, P. . radii on Ma- 

 tricaria. 



The action of various species of Cysto- 

 pus is summarized to show the quite differ- 

 ent effects produced by this genus when 

 compared with the closely related Perono- 

 spora. It appears that : 



1. There are notable changes in the form, dimen- 

 sions and contents of the individual cells of the floral 

 organs. 



2. New types of cell arrangement are produced. 



3. The myrosin (in mustards) is translocalized. 



4. The pollen-spore mother cells are converted 

 into vegetative cells. 



The action of TJromyces scutellatus on 

 the flowers of Euphorbia cyparissias re- 

 calls the well-known case of Lychnis at- 

 tacked by Ustilago antherarum,* which is 

 discussed anew by Molliard. In Euphorbia 

 cyparissias the effect of the rust is (1) to 

 transform the staminate flowers into pistil- 

 late or monoclinous and the monoclinous 

 flowers into pistillate ; (2) to cause atrophy 

 of the pollen and embryo sac spoi-es; (3) to 

 cause hypertrophy of the parenchyma in all 

 organs. 



The most notable result of smut attacks 

 upon flowers is the so-called parasitic cas- 



* Giard and Mangin. Notes sur la castration para- 

 sitaire du Lychnis dioica, L. — Bull. Sc. Nat. de Fr. et 

 Belg. II. 150; also Vuillemin: Sur les efiets du para- 

 sitism de I'ustilago antherarum, Comptes Eend. 

 Hebd. CXIII. 662, 1891, and review of this paper in 

 Botan. Gazette. 17: 17. 1891. 



