No. 1, August, 1920] MORPHOLOGY AND TAXONOMY, ALGAE 79 



one, Synedra anguinea, S. incisa, Eunotia Stevemonii, Pinnularia Hagelsteinii, Nilzchia 

 scmicostata, and Surirella Palmeri. Navicula Attwooddii M. Perag. and an abnormal form of 

 Aulodiscus oregonus Harv. & Bail, are discussed. — P. A. Munz. 



595. Bristol, B. Muriel. On the alga-flora of some desiccated English soils : an impor- 

 tant factor in soil biology. Ann. Botany 34: 35-80. PI. 11. 12 fig. 1920.— By means of water 

 cultures it is show that there is a widely distributed plant assorial ion in cultivated soils con- 

 sisting of moss protonema and algae. Sixty-four species and varieties of algae were identi- 

 fied. All these algae can withstand from four to twenty-six weeks desiccation. Descriptions 

 of the algae including six new species are given. — E. N. Transeau. 



596. Bullock-Webster, G. R. A new nitella. Irish Nat. 28: 1-3. PL 1. 1919 — 

 Nilella spanioclema, a new species collected at Lough Shannach, County Donegal, Ireland. — 

 W. E. Praeger. 



597. Carter, Nellie. On the cytology of two species of Characiopsis. New Phytol. 18: 

 177-186. 8 fig. 1919.— See Bot. Absts. 5, Entry 118. 



598. Church, A. H. Historical Review of the Florideae II. Jour. Botany 57: 329-334. 

 1919 (continued from Ibid. 57: 304). — The Florideae represent an independent line of evolu- 

 tion in the sea from the ancestral stage of encysted plankton-flagellates, attaining somatic 

 and reproductive specialization along their own lines. Nuclear migrations and haustorial 

 connections of the carpospore are but an extension of secondary pit-connections and migration 

 in the somatic organization. Cenocytic decadence of the trophocyte is paralleled by the sec- 

 ondary coenocytic organization in the vegetative soma of distinct generic types. — Progressive 

 differentiation of the sex mechanism leads through inevitable stages to oogamy and fertiliza- 

 tion in situ, following the failure of the oospore to be discharged, thus giving rise to many 

 separate phyla of algae. Though efficient in economy of materials, this method leaves 

 dispersal unprovided for. — Most important in the Floridae, however, is not the fertilization 

 in situ with a parasite zygote and a sporophyte generation producing spores, but the presence 

 of three successive generations as follows: (I.) Gametophyte, (II.) Carposporophyte (dip- 

 loid) and (III.) Tetrasporophyte (haploid). In (I.) there is the most complete economy 

 in the sexual process. The gametes are expressed as mere nuclei, a condition otherwise at- 

 tained only in the Angiosperms. There is also post-sexual nutrition. This is made possible 

 by the mechanism of the pit-connections left open at the base of the young carpogonium. 

 In (II.) the generation is asexual. Whether it be haploid or diploid does not matter, but 

 there has been no inducement to a haploid condition. It is a very much reduced stage. In 

 (III.) the spores are immediately dispersed and take the small chance of immediate germina- 

 tion. They grow to a free autotropic soma, but there is a reduction to the haploid condition 

 at the formation of tetraspores. — The haploid spores on germination give a haploid soma which 

 is normally free and autotropic, and which may be sexual and repeat the sequence, though 

 it may as well be asexual. Of special interest are cases where the tetraspore formation is 

 wanting and reduction is otherwise provided for, but the locus of the process is wholly sub- 

 sidiary and secondary. The condition in Scinaia and Nemalion in this respect is discussed. 

 — The clue to the peculiar behavior of the zygote and young carposporophyte in its relation 

 to the auxiliary cells is seen in its practically holoparasitic habit. The passage of food mater- 

 ial quickly is rendered possible by the mechanism of secondary pit-connections dependent on 

 the soft penetrable wall-membrane. — The clearest view of the Florideae is that they consist 

 of a multitude of distinct phyla as the survivors of a specialized and circumscribed ancient 

 race of Marine Algae. All of the living representatives are on a closely comparable physio- 

 logical plane, but the phyla diverge as to somatic construction and organization and as to 

 internal economy, becoming more specialized in relation to the parasitic carposporophyte. — 

 The phases of haustorial connection, progressively more intricate and devastating in relation 

 to the parental thallus they drain, constitute but one aspect of the question. The produc- 

 tion of the cystocarpic wall after fertilization passing to the initiation of these structures be- 

 fore fertilisation represents a specializal ion of great significance. A true phytogenetic classi- 



