426 Fortpflanzung. 



ticulum condenses to form the chromosonies. In many cases they are formed by 

 the condensation of the reticulum along the two sides of certain lines, giving 

 two parallel halves. In other cases the dual character of the chromosome begins 

 to appear much later. No prochromosomes could be found in the resting nucleus. 



Gates (London). 



1178) Baebmaim, F. M., A new type of spermogonium and fertiliza- 

 tion in Collema. In: Annais of Botany, Vol. 26, Heft 2, S. 747 — 760, pl. 69, 

 1912. 



The reproductive organs of the Lichens have long been a subject of interest, 

 as they resemble in certain features both the red Algae and the Ascomycetes. 

 This paper describes a new type of sexual organs in the Liehen Collema pulposiim. 

 In this liehen the spermatia or male cells are not borne in spermogonia, as in 

 other lichens, but are borne directly on hyphae Avhich remain below the sur- 

 face of the thallus. The carpogonia, or female sex-organs are, like those of other 

 lichens, embedded in the thallus; and they consist of a basal coiled ascogonium 

 and a long terminal trichogyne. But in this peculiar liehen the trichogyne, instead 

 of projecting from the surface of the liehen, grows horizontally in the thallus 

 towards where the spermatia are produced. The trichogyne is attracted (pro- 

 bably chemotactically) by the spermatia and the two fmally fuse, resulting in 

 normal fertilization. The whole sexual apparatus thus remains submerged in the 

 thallus. Gates (London). 



1179) Kershaw, E. M. (Manchester, University), Structure and develop- 

 ment of the ovule of Boivenia spcctabilis. In: Annais of Botany, Vol. 26, 

 Heft 2, S. 625—646, pl. 61, figs. 16, 1912. 



The ovule development in this interesting Cycad is described and compared 

 with that of other Cycads. The formation of the pollen Chamber and ovule is also 

 compared with that of the fossil group of Pteridosperms. The development re- 

 sembles that of other Cycads in a general way, with certain peculiarities. The 

 male gametophyte apparently resembles that of Zamia, w^hile the general struc- 

 ture of the ovule agrees closely with seeds of the fossil Medulloseae. 



Gates (London). 



1180) Meek, C. F. U. (Manchester, University), The Correlation of Soma- 

 tic Characters and Chromatin Rod-Iengths, being a further study 

 of Chromosome Dimensions. In: Journ. Linnaean Soc. London. (Zool.), 

 Vol. 32, Nr. 213, S. 107—119, 1912. 



A study of the spermatogonial and spermatocyte chromosomes, in the grass- 

 hopper Stenohothrus curüpcnnis confirms the authors conclusions with regard to 

 chromosome width and length previously set forth. The four species of Steno- 

 hothrus examined all have five similar short chromosomes, but differ in the longer 

 chromosomes. An attempt to correlate the somatic characters of the species with 

 the lengths of these long chromosomes does not lead to positive results. 



Doncaster (Cambridge). 



1181) Smith, Geoffrey (Oxford, University), Studies in the Experimental 

 analysis of Sex. Part. 9. On spermatogenesis and the Formation of 

 Giant spermatozoa in Hybrid Pigeons. In: Quart. Journ. Microscop. 

 Science, Vol. 58, Pt. 1, S. 159— 170, 1 plate, 1912. 



Three male hybrids were obtained from a male Pigeon maled to a female 

 domestic dove [Collared Turtledove, Turtur risorms^ Ref.]. The hybrids attempted 



