176 MORPHOLOGY AND TAXONOMY OF FUNGI, ETC. [Bot. Absts., Vol. VI, 



MORPHOLOGY AND TAXONOMY OF FUNGI, LICHENS, BACTERIA, 



AND MYXOMYCETES 



H. M. Fitzpatbick, Editor 



FUNGI 



1213. Adams, J. F. Rusts on conifers in Pennsylvania. Pennsylvania Agric. Exp. Sta. 

 Bull. 160. 30 p., 10 Jig. 1920. — A brief characterization of the coniferous rusts, an enumera- 

 tion of the species known to occur in the State, citations of collections with collectors names, 

 and an index to species and hosts. The list is composed of Peridermium Comptoniae, P. 

 pyriforme, P. cerebrum, P. strobi, on stems of Pinus spp.; P. acicolum, P. delicatulum, 

 P. carneum, P. Helianthi, P. Ipomoea, on leaves of Pinus spp. ; P. Peckii, P. Hydrangeae, 

 on leaves of Tsuga; P. columnare on leaves of Abies; Caeoma Abietis-canadensis on twigs and 

 cones of Tsuga; Gymnosporangium Juniper i-virginianae, G. globosum, G. germinate, G. effu- 

 sum, G. Nidus-avis, G. clavariaeforme, G. botryapites, G. trachysorum, on Juniperus spp., and 

 six other rusts which have been collected only in the uredinial or telial stages. — C. R. Orton. 



1214. Adams, J. F. Sexual fusions and development of the sexual organs in the Peri- 

 dermiums. Pennsylvania Agric. Exp. Sta. Bull. 160: 31-76. 5 pi. 1920. — "Sexual cell 

 fusions and development of the aecium were studied in five species of Peridermium, P. Comp- 

 toniae, P. pyriforme, P. acicolum, P. Peckii and P. balsameum. In the two stem forms stud- 

 ied (P. Comptoniae and P. pyriforme) the pycnia have a caeomoid type of fructification, 

 being apparently unlimited in their development. These caeomoid pycnia originate between 

 the cork layer and cortical parenchyma and thus are to be considered cortical in origin and 

 not sub-epidermal. They are irregular in outline and the margins are not delimited, but con- 

 sist of a spreading plectenchyma. The pycnial layer appears as a broad, flat crust-like layer 

 with no definite aperture for the escape of the pycniospores which apparently depend for their 

 escape upon the irregular cracking of the overlying tissue. They were observed developing 

 in the tissue overlying the young aecia as well as in the adjacent tissue. The pycnia in the 

 leaf forms are early delimited. They are conoidal to hemispherical in outline and possess a 

 definite aperture for the escape of the pycniospores. The gametophoric hyphae form a con- 

 spicuous palisade layer in the aecial primordia of P. Comptoniae, P. pyriforme, and P. aci- 

 colum. The pseudoparenchyma of the aecial primordia is made up of the peripheral portions 

 (sterile cells) of the gametophoric hyphae and is sharply defined from the fertile layer. The 

 sterile cells of the gametophoric hyphae are homologous to the so-called "buffer cells" of the 

 caeoma. Sexual cell fusions occur between adjacent fertile cells of similar size and position 

 in two gametophoric hyphae. A dissolution of the walls occurs usually at the upper ends or 

 where they come in contact. This phenomenon proceeds so as to result ultimately in the com- 

 plete disappearance of the contact walls, thus forming a fusion cell. The development of a 

 peridium appears to be associated in these forms with an extensive development of pseudo- 

 parenchyma. The central arch of the peridium is composed of the apical metamorphosed 

 aeciospores of the inner spore chains. An exception is found in the aecium of P. acicolum 

 where the division of the peridial initial cells in the central arch cuts off an intercalary cell 

 above. The lateral portion of the peridium consists entirely of metamorphosed spores. In 

 P. Comptoniae the central arch of the peridium is two to four cells in thickness. The size of 

 the aecium in P. acicolum, P. Peckii and P. balsameum is early determined by the breadth 

 of the primordium. The aecia of P. Comptoniae and P. pyriforme resemble the caeoma in 

 their indeterminate growth and the aecidium cup in their deep origin and the presence of 

 a peridium. In P. Comptoniae and P. pyriforme the effect of the development of the pycnia 

 and aecia is such as to kill the immediately adjacent tissue. This tissue is sloughed off in 

 the late summer with the formation of a new cork layer." — C. R. Orton. 



1215. Bezssonoff, [ — .] Sur l'obtention experimental de la sexualite chez les champig- 

 nons et orientee sur la structure typique du plasma sexuel. [On the initiation of sexual repro- 



