168 



IIJK noTANIVAL MAdAZINE. 



[Vul. XX'XIIl. No. 39'-'. 



The f(jllo\viii_n; table is compiled from the dnla alrcad}- given for 

 illustration. Tints : 



Table \TII. Blcchnum nipponjcum. 



Cone. Knop. 



0.50 



Average No. Arch. 



O -1 



1.26 



A brief note may l^e added on the rate of sex diftcrentiation 

 tneasured bv the nximbcr of antlieridia and archegonia in the case of 

 Blcchnum nipponicum. The number of prothaliia which bears anthc- 

 ridia raj)idly increases and reaches over fifty per cent between forty 

 to fifty five days after sowing, while that oi archegonia is more 

 gradual. The curves of increase in the latter are nearl\- linear. The 

 tendency is similar both in 0.25 and O.f) per cent nutrient solutions. 

 The actual numbers are as follows : 



* Grown under weak illumination, 

 t frrown under stronger ilhimination. 



