3i8 BOTANICAL GAZETTE [October 



fungi 



nberry. Three new genera are described: Plagiorhabdus 



(2 spp.), Bolhrodiscusy and Acanthorhynchus. — O. Stapf (Jour. Linn. Soc. 



Bot. 38:6-17. 1907) has 

 thaceae, to include species 



(H. 



to Ptyssiglottis; 19 species are recognized, 11 of which are new. — R. Lauter- 



BORN 



{Thioploca) of sulfur bacteria, belonging to the Beggiatoaceae. — J. M. C. 



The male gametophyte of the podocarps.^ — Jeffrey and Chrysler^^ have 

 been able to examine the male gametophyte of certain species of Podocarpus and 

 Dacrydium, as well as of Agathis, obtained from New Zealand and Java, so far 

 as material preserved in alcohol or formalin would permit. The conspicuous fea- 

 ture is the development of a prothallial tissue, by diA-ision of the two original pro- 

 tballial cells, consisting in some cases of as many as eight cells. The walls of this 

 tissue break down and the nuclei are freed, even from their cytoplasm, and swarm 

 into the pollen tube. The authors do not regard this as a primitive feature, but 

 consider the "ground plan" of this development as indicating the derivation of 

 the podocarps and araucarians from an ancestral stock allied to the Abietineae, 

 This feature also indicates that the podocarps and araucarians may be more 

 nearly allied than has been supposed. — J. M. C. 



Infection experim.ents with mildew. — Reed^^ has been investigating the 

 question of "physiological species" among the mildews. Recent work on mil- 

 dews has indicated that each genus, and often each species of host plant, has its 

 own particular specialized form. Infection experiments were conducted with 

 twenty-three different varieties of commonly cultivated cucurbits, representing 

 five species and three genera (Cucurbita, Cucurais, and Lagenaria). Each of these 

 hosts was readily infected when inoculated with the conidia taken from any other. 

 There was no difference in the infecting power of the mildew on the different species 

 and genera, and there is no evidence of any specialization in the mildew of the 

 Cucurbitaceae. — ^J. M, C. 



A lycopod with a seedlike structure. — ^liss Benson^^ has investigated the 

 reproductive structures of Bertrand's Miadesmia memhranaceay a herbaceous 



1 



paleozoic lycopod. The megasporangium develops a single thin-walled spore, 

 "which in development and structure resembles an embr}'o sac and germinates 

 in sitiiV The sporangium is surrounded by an integument with a small micropyle, 

 which is surrounded by numerous long processes of the integument that "formed 



18 Jepprey, E. C, and Chrysler, M. A., The microgametophyte of the Podo- 

 carpineae. Amer. Nat. 41:355-364. figs. 5. 1907. 



19 Reed, George M., Infection experiments with the mildew on cucurbits, Ery- 

 siphe cichoracearum DC. Trans. Wis. Acad. Sci. 15:527-547. 1907. 



^° BensoNj M., Miadesmia memhranacea Bertrand; a new paleozoic lycopod 



with a seed-like structure. 



London. Tune 



