ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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fungus-mycele. In the prothallium of the second type there is a much 
more pronounced differentiation of tissues ; it is small and resembles 
a turnip crowned by a colourless lobed crest, and bears antherids and 
archegones on its upper surface. The cortex contains a fungus-mycele. 
In the third type, the prothallium is tuber-like or elongated, colourless, 
and with less strongly differentiated tissues, consisting of a central 
part which bears the antherids and archegones, and a peripheral cortical 
portion. The sexual organs are surrounded by paraphyses ; the pro- 
thallium has the faculty of branching adventitiously. 
The author gives a full description of the development of the 
embryo in L. clavatum. The fertilised oosphere lengthens into a pear- 
shape before it breaks up into a larger suspensor-cell facing the neck 
of the archegone and a smaller embryonal cell. This latter divides 
into eight cells, the foot originating from the four lower ones, the shoot 
and the first endogenous root from the four upper. The foot remains 
enclosed in the prothallium ; the shoot produces two opposite coty- 
ledons. The processes are similar in L. complanatum. In L. Selago 
the foot is developed outside the prothallium, and only one cotyledon 
is formed. 
The lateral roots of Lycopodium are not produced from the peri cam- 
bium, as stated by van Tieghem and Douliot, but from the cortex. 
The author then discusses the systematic position of the Lycopodiaceae, 
which he thinks is not near to the Selaginellacese. While the structure 
of the sexual generation approaches that of Mosses, the structure of 
the sporophyte comes much nearer to that of the higher plants. The 
genus Lycopodium, should be broken up into several. 
Stem of Lycopodium.* — Mr. C. E. Jones classifies the species of 
Lycopodium in two groups, according to the anatomical structure of the 
stem: — (1) L. clavatum , alpinum , Phlegmaria , and cernuum. The oval 
stelic arrangement is marked by a considerable amount of xylem, 
broken up into patches by bands of phloem. Large empty cells, sieve- 
tubes, appear in the centre of these bands. Protophloems and proto- 
xylems are external, forming a continuous ring. The cells of the 
cortex lying just outside, the endodermal cells are thickened and ligni- 
fied, forming a third concentric zone. (2) L. squarrosum , dichotomum , 
and nummular if olium. The phloems occur as islands in the sea of 
xylem, or as inserted peninsulas ; they are built up centrally, with the 
apparent sieve-tubes in the centre. Protoxylems are well marked and 
lie externally ; but protophloems are not to be distinguished. L. Dal - 
housieanum and Selago are intermediate between these types. 
Division of the Chromosomes in the Formation of the Spores of 
Ferns. I — The following are the main results obtained by Mr. W. C. 
Stevens from an investigation of this process in Scolopendrium vulgar e, 
Cystopteris fragilis, and Pteris aquilina. From the original archespore 
there arise sixteen spore-mother-cells. The chromosomes of the first 
division are short and stout, differing in this respect from those result- 
ing from vegetative division. A numerical reduction of the chromo- 
somes takes place during the prophasis of the first division of the 
* Ann. of Bot., xii. (1898) pp. 558-9. 
t Ber. Deutsch. Bot. Ges., xvi. (1898) pp. 261-5 (1 pi.). 
