1300 Journal of Applied Microscopy 



He agrees with Johnson and Strasburger in not regarding the fusion of polar 

 nuclei as a sexual process, but merely a physiological phenomenon. The whole 

 endosperm as well as the antipodal cells are regarded as gametophytic struc- 

 tures. Gnefii?fi, as described by Lotsy, furnishes the nearest approach to the 

 embryo-sac structures of Peperomia. 



The author had several species of Peperomia germinated at Kew and they 

 proved to be genuine Dicotyledons. Attention is called to significant resem- 

 blances to the lower Monocotyledons, especially the Araceae. The conclusion is 

 reached that Peperomia is the most primitive type of the Dicotyledons and that 

 the resemblances between the Piperacese and lower Monocotyledons suggests 

 that the divergence of the two groups may have occurred very early. 



c. J. c. 



Timberlake, H. G. Swarm Spore Formation in ^"^ this short preliminary note Prof. 

 Hydrodictyon utriculatum Roth. Bot. Gaz. Timberlake announces some interest- 

 ^' ^ ■ ing results of his work on Hydrodictyon. 



Material was fixed in a fluid recommended by Eisen. 



(1) Iridium chloride (0.5 per cent, aqueous solution) - 100 c. c. 

 Glacial acetic acid. ----------- 1 c. c. 



(2) Iridium chloride (1 per cent, aqueous solution) - - 100 c. c. 



Glacial acetic acid, - ---------- 3 c. c. 



The second solution gave better results. There are no dififerentiated chrom- 

 atophores, but the chlorophyll is distributed throughout the cytoplasm. The 

 nuclei have the structure of those of higher plants. When the segments of 

 older nets are to give rise to swarm spores, cleavage furrows are run in, at first 

 cutting out large multinucleated portions of cytoplasm, which are then divided 

 and subdivided until each mass contains only a single nucleus. Each mass then 

 gives rise to a single uninucleated, biciliated spore. c. j. c. 



Palisa, J. Die Entvvickelungsgeschichte der Among many ferns the power of regen- 

 Regenerationsknospen, welche an den >^- i i i i tt • 



Grundstiicken isolirter Wedel von Cystop- oration has long been known. Hem- 



teris-Arten entstehen. Ber. d. deutsch. bot. reicher, in studying the resistance of 



Gesell, 18 : 398-410, pi. 14, 1900. , .... , , r /-^ - . ^ ■ i jl-j- 



' jv t > r t. y adventitious buds of Cystoptcris hulbifera 



to draught, found that after the central apical part of the bud had decayed, small 



plantlets often arose from the outer parts, and he ascertained by experiments 



that they arose from the bud-scales. He also found that similar buds arose from 



the basal part of the fronds of other ferns. The developmental history of the 



adventitious buds of Cystoptcris and other ferns has been determined by Hein- 



reicher, and in the present article Palisa gives an account of the development of 



these regeneration buds. He worked mainly on two forms, Cystoptcris hulbifera 



and C. Montana. On the former, the buds arise from the outer scales of the 



adventitious buds, and on the latter from the basal portion of the fronds. The 



scales of the former were removed and placed in moist sand under glass tubes, 



while in the latter case the formation of buds was invoked by cutting off from the 



underground rhizome the still unrolled frond blade. 



Palisa endeavored to answer two questions ; first, are there any predetermined 



