JOURNAL OF MICROSCOPICAL SCIENCE. 



DESCRIPTION OF PLATES X & XL 



Illustrating Dr. Farlow's paper on an Asexual Growth from 

 the Prothallus of Pteris cretica. 



Figs. 



1— 3. — Different forms of the prothallus of Pteris cretica, with antheridia 

 and root hairs on their lower portions. 



a. Scalar if orm duct. 



b. First leaf. 

 r. Root. 



*. Stem bud. 



4. — Vertical section of prothallus somewhat less advanced than in fig. 3 ; 

 the letters indicate the same structures as before. 



5. — Prothallus producing two leaves side by side; a, scalariform ducts, 

 by leaf from upper, b', leaf from under side. 



6. — Longitudinal section of prothallus in fig. 1, in the direction of the 

 arrows. 



7. — Longitudinal section parallel to y in fig. 6, and more highly mag- 

 nified. 



z. Two of the archegonium-like group of four cells, which are 

 seen to have no immediate relation with the subjacent scala- 

 riform ducts. 



