180 Shiv Ram Kashyap. — The Structure and Development of 
9. The archegonium has a single neck-canal cell, which is another 
point of resemblance with the prothallus of Lycopodium cernuum. It must 
be pointed out in this connexion that although the prothallus of L . 
cernuum is generally accepted to be of a primitive type (Lang), still it has 
only a single neck-canal cell. This suggests that the larger number of the 
neck-canal cells in other species of Lycopodium is a secondary feature. 
The features pointed out above indicate in most cases a clear affinity 
with the prothallus of Lycopodium cernuum , and when we remember the 
great difference exhibited by the sporophyte generations of Equisetum and 
T.ycopodium in their external characters and internal anatomy, the re- 
semblance in the prothalli is at least striking. 
My cordial thanks are due to Professor A. C. Seward, Cambridge, who 
kindly corrected the first proofs. I have seen the final proofs myself, and 
am alone responsible for everything contained in this paper. 
Literature cited. 
Aitchison, J. E. T. : A Catalogue of the Plants of the Punjab and Sindh. 1869. 
Baker, J. G. : Handbook of the Fern-allies. 1887. 
Bruchmann, H. : Flora. 1910. 
Buchtien, O. : Entwickelungsgeschichte des Prothallium von Equisetum. 1887. 
Chamberlain, C. J. : Methods in Plant Histology. 
Goebel, K. : Organography of Plants, Part II. English translation. 1905. 
Lang, W. H. : The Prothallus of Lycopodium clavatum. Ann. Bot., June, 1899. 
Lotsy, J. P. : Vortrage iiber botanische Stammesgeschichte. 1909. 
Sharp, Lester W. : Spermatogenesis in Equisetum. Bot. Gaz., 1912. 
Stewart, J. L. : Punjab Plants. 1869. 
Tubeuf, — : Plant Diseases. English translation by W. G. Smith. 1897. 
EXPLANATION OF FIGURES IN THE TEXT. 
Fig. 1. First wall in the spore, x 300. 
Figs. 2-13. Early stages in the development of the prothallus. Figs. 2, 3, 4, 7, 8, 9, 10 x 300. 
Fig. 13 x 125. Figs. 6, 11, 12 x 70. Figs. 3, 7, and 13 show the ‘ primary tubercle’. r in all 
cases indicates the rhizoid cell. 
Figs. 14, 15. Prothalli, three weeks old. x 70. 
Fig. 16 (a and b). Two older prothalli from the ventral side. Rhizoids removed. The posterior 
notch is seen in a\ none in b. m = meristem. x 4. From a shady place. 
Fig. 17. A prothallus rather older than Fig. 16. Ventral view, x 2. The fissures showing 
the division of the prothallus are seen, m = meristem. 
Fig. 18. A well -grown prothallus growing on the soil. Nat. size. From a shady place. 
Fig. 19. Another compact prothallus kept inside a room and watered plentifully for about one 
month. The lobes formed during that time are long and loose. Nat. size. Four young plants are 
seen at places marked x . 
