ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 643 



Jamaica the morphology was investigated. . It was found that : — 1. The 

 tuberous stock is traversed by a stele showing a bulky central pith and 

 transversely widened leaf -gaps. It is of the same type as Eu-Ophioglos- 

 sum. 2. The leaf-trace originates as two distinct strands inserted widely 

 apart, right and left of the leaf-gap. 8. The spikes, which vary in 

 number, originate like that of Eu-Ophioglossum • the lowest usually 

 median, the rest usually intramarginal. The spikes branch frequently 

 and irregularly. 4. The single spike of Eu-Ophioglossum appears to be 

 the morphological unit ; and the numerous spikes of Ophioglossum pal- 

 matum&ie due to " pleiogeny " (a new term invented to denote an increase 

 of organs from a given unit, an increase by branching, interpolation, 

 etc.), and are not directly referable to normal pinnae any more than are 

 the irregular lobes of its sterile lamina. 5. Phyletically 0. pendulum, 

 0. intermedium, and 0. simplex form a derivative series from Eu-Ophio- 

 glossum. Ophioglossum palmatum represents a parallel, but probably a 

 distinct line, which has carried amplification of the leaf further. The 

 divided leaf -trace which they all show confirms the derivative character 

 of both lines. 6. There is increasing evidence of the alliance of the 

 Ophioglossacere with the Filicales — namely in the direction of the Cceno- 

 pteridaa and of the Osmundaceaa. 7. The normal spike of Ophioglossum 

 on anatomical and other grounds may be held to be ultimately of pinna- 

 nature ; perhaps in most cases a result of pinna-fusion, according to the 

 theory of Roeper. But this unit is subject to repetition in 0. palmatum. 

 8. The vascular supply to the Ophioglossaceous spike being normally 

 marginal, or from an abaxial pinna-gap, it differs from that to the spore- 

 producing organ in the Psilotacese and Sphenophyllaceaa, where it conies 

 off from the adaxial face of the foliar strand, or in the middle region of 

 it. This difference, if it be found to be constant, may provide a real and 

 valid anatomical distinction. 



Forms of Ophioglossum.* — W. Freiberg publishes notes on some 

 plurispicate forms of Ophioglossum vulgatum. He gives new names to 

 three of them and adds some figures. He also cites other examples which 

 have been previously described. He can put forward no reason for the 

 production of these monstrosities. 



Origin of Medulla in Ophioglossacese.f — F. 0. Bower writes on the 

 primary xylem and the origin of medullation in the Ophioglossaceie. He 

 sums up his observations at some length and draws the general conclusion 

 that the pith in the Ophioglossacese is primarily, though not always 

 wholly, of intrastelar origin, and that the pith is, in part at least, intra- 

 xylic in origin. 



Medullation in the Pteridophyta.J — F. 0. Bower replies to the 

 views expressed by Jeffrey on the origin of vascular structures. Jeffrey 

 says that " the pith must in all cases be regarded as a derivation of the 

 cortex which has become more or less completely sequestered within the 

 stele." Bower maintains " that there is no rigid law of medullation " ; 



* Allgem. Bot. Zeitschr., xvii. (1911) pp. 81-3 (1 pi.). 

 + Ann. of Bot., xxv. (1911) pp. 537 58 (2 pis.). 

 % Ann. of Bot,, xxv. (1911) pp. 555 -74 (1 pi.). 



