January 27, l.)Co.] 



SCIENCE. 



143 



the conidiphore and conidial fructification, 

 the description of the . conidia themselves, 

 with occasional unique characters which 

 identify special forms— such as the forma- 

 tion of selerotia. Cultures, diagrams and 

 card descriptions of species of Penicillium 

 were presented to illustrate the charac- 

 ters mentioned. 



The Asciferous Stage of Gloeosporium 



Psidii: John L. Sheldon. 



By means of artificial cultures and in- 

 oculations. Dr. Sheldon Avas able to study 

 the life-history of Gloeosporium Psidii G. 

 Del., a fungus which causes the 'mummy 

 disease' of the guava. The Gloeosporium 

 stage of the fungus closely resembled the 

 Gloeosporium stage of the 'bitter-rot' fun- 

 gus (Glomerella) of the apple as deter- 

 mined by himself and other investigators. 

 In old cultures on apple-agar, masses of 

 peritheeia were produced which resembled 

 those of Glomerella both in shape and in 

 structure, and also in the size and shape of 

 the ascospores. The results indicate that 

 the two fungi may be identical, although 

 there were certain characteristics of the 

 two that were not quite the same. The 

 investigation will be continued. 



Cytological Studies of Sapromyces and 



Rhipidium: Cyrus A. King. 



Sapromyces and Ehipidium both belong 

 to the SeptomelaccEe, which family is placed 

 by Schroeter in the Saprolegniineae. 



In zoospore formation the individuals are 

 separated by the severing of connecting 

 cytoplasmic meshes. This process begins 

 on the interior if there is a vacuole present. 

 In some cases, at least, there is an indirect 

 nuclear division in the zoosyyorangium of 

 Sapromyces. In the oogonia of Sapromyces 

 there is one mitosis and there is probably 

 one in Rhipidirim also. In both forms dur- 

 ing oogenesis the supernumerary nuclei 

 migrate to the periphery where they are 

 cut off in a periplasm. This periplasm in 



Sapromyces is very rudimentary. The 

 fertilization tube in Rliipidium is of 

 oogonial origin, although it is possibly of 

 antheridial origin in Sapromyces. A con- 

 spicuous differentiated region correspond- 

 ing to the oocentrum of Trow is seen in 

 Rhipidium. The reticulations on the 

 oospore wall of Rhipidium are probably 

 homologous with the radiating walls be- 

 tween the peripheral cells of Acosospora. 

 The structure of the oogonium and the 

 processes in oogenesis show this group to 

 be related to the Peronosporineae and it is 

 siiggested that they be placed in this cohort 

 as follows: Perono-sporineae— Albuginaceje, 

 Peronosporaceae, Septomelacefe, Saproleg- 

 niineae — Saprolegniaceae. 



A Study of the North American Coleo- 



sporiacece: J. C. Arthur. 



A list of twenty-four .species is presented, 

 some of them now described for the first 

 time. The presentation chiefly deals with 

 the method employed in discriminating be- 

 tween the .species, their degree of relation- 

 ship, and their distribution. 



Nomenclatorial Type Specimens of Plant 



Species: A. S. Hitchcock. 



In systematic botany there is an increas- 

 ing tendency to base species upon definite 

 specimens. Older authors did not do this. 

 It becomes necessary to decide upon rules 

 for selecting the specimen upon which spe- 

 cies .should be based when these are not 

 definitely indicated. The present paper is 

 a discussion of such rules. 



Cultures of Wood-Inhahiting Fungi: Per- 



LEY SpAULDING. 



It has been found easier to make cultures 

 of wood-rotting fungi from actively grow- 

 ing mycelium than from the spores. Agar 

 made from infusions of the species of wood 

 which the fungus is found iipon, usually 

 serve to start growth of the mycelium at 

 first. They can then be transferred to 

 tubes of sterilized green wood of the suit- 



