ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 279 



rently antherozoids, escape, pointed at one end, but so minute that 

 their structure could not be clearly made out. If these bodies are 

 really antherozoids, the minute cells from which they escape are the 

 mother-cells of the antherozoids, and the cells of the antheridium 

 the mother-cells of these again. The only other explanation seems 

 to be that these motile bodies do not belong to the Lycopodium pro- 

 thallium at all, but that they are the antherozoids of a parasitic 

 Chytridium, The entire antheridium originates from a central cell 

 abundantly filled with nutrient substances, which divides rapidly in 

 all directions. No archegonia were found on any of the prothallia. 



South American Isoetes.* — A. Franchet describes a new species 

 of Isoetes, I. Savatieri, from Patagonia, probably further south than 

 any species previously known. It belongs to the section Amphibise, 

 and is distinguished by its great heteromorphism, according as it 

 grows submerged or on dry land. 



Development of the Vegetative Organs of SelagineUa spinnlosa.t 

 — According to H. Bruchmann, the apical growth of the stem and 

 branches in this plant is governed by a group of cells which gives off 

 lateral segments for the widening of the apes by walls placed at right 

 angles to the surface. The formation of the entire tissue of the 

 interior of the stem is referable to the segmentation in a direction 

 parallel to the surface of these segments and of the initial group. 

 The apical growth of SelagineUa spinulosa resembles therefore that 

 shown by the same author, to occur in Isoetes lacustris, I. Duriaei, 

 I. Malinverniana, SelagineUa Lyallii, Lycopodium Selago, L. annotinum, 

 L. alpinum, L. inundatum, L. clavatum, and L. Chamcecyparissus. 

 The first branching of the young plant is strictly dichotomous, 

 always at right angles to the cotyledonary plane. It is preceded by 

 an increase in the initial group, by which the energy of growth is 

 transferred from the centre of the apex to its sides, two new apices in 

 divergent directions taking the place of the old one. All the succeed- 

 ing branchings take place in one plane, at right angles to the plane of 

 dichotomy, and monopodially. SelagineUa spinulosa has no rhizophore. 

 The roots have their origin at the base of the tigellum, and are con- 

 structed out of two initial groups. One of these corresponds to the 

 initial group of the apex of the stem ; from it arise the dermatogen, 

 periblem, and plerome of the root. Above this initial group lies that 

 of the calyptrogen. The branchings of the root are always dichoto- 

 mous ; each plane of dichotomy is at right angles to the preceding 

 one. 



Muscineae. 

 Archegonium and Sporogonium of Muscineae. | — L'Abbe Hy has 

 examined the structure of the archegonium and the development of the 

 sporogonium in a large number of species of Muscineae, belonging 

 especially to the true Mosses. He is led to dissent from the union of 

 the Muscineae with the Vascular Cryptogams into one class of Arche- 



* Bull. Soc. Bot. France, xxxi. (1884) pp. 395-6. 



t Zeitschr. f. Naturwiss., 1884, pp. 356-7. 



X Ann. Sci. Nat, (Bot.), xviii. (1884) pp. 105-206 (6 pis.). 



