38 Mr Allan E. Grant on the 



Plate IV. 



Fig. 13. Fruit uf Bornia radiatay Brongn. (Pothocites caJaniitoidea, 

 Kidst.), showing a perfect spike compo.sed of eight 

 segments attached to a calamitic stem. Leaves are given 

 off from the nodal regions of both stem and fruit, some 

 of which show the dichotomous nature of the foliage. 

 From the Calciferous Sandstone series, Glencartholm, 

 Eskdale. 

 Fig. 14. Bornia m'7m^«, Brongn. Enlarged sketch of the impres- 

 sion of the hasal portion of the fruit of the specimen 

 from Eaehurn's Pit, West Calder, showing transverse 

 bars and node on stem. 

 Fig. 15. Lowest node of tlie stem of the Eskdale specimen, showing 



scars from which leaves have fallen. (Enlarged.) 

 Fig. 16. Two unopened sporangia, from an upper segment of the 



spike of the same specimen. (Enlarged.) 

 Fig. 17. One of the open (stellate) s])orangia, from the lowest 



segment of the same example. (Enlarged.) 

 Fig. 18. Sphenophyllura tenerrirmira (Ett. MS.), Stur. From the 

 Calciferous Sandstone series, Raw Camps, East Calder. 



Figs. 6-11, 14 and 18, are from specimens in the collection of the 

 Geological Survey of Scotland, Edinburgh. 



The MuUimicIeated Condition oj the Vegetable Cell, with 

 some special Researches relating to Cell Morphology. 

 By Allan E. Grant. (Plates Y. and VI.) 



(Read 14th June 1883.; 



[This is one of two competing Essays, to which liulf ol' 

 the Society's Students' Prize of £10 was adjudicated.] 



Part I. — Previous Researches. 



Professor Schmitz* of Bonn showed that in the cells of 

 Siphonocladlacece (a family instituted by himself) there is 

 often a great number of nuclei embedded in the laj'er of 

 chlorophyll, and regularly distributed through it at intervals. 

 Thus, in the genus Valonia of this family, there may be 

 several hundred nuclei in each of the larger cells. Divi- 

 sion of these takes place, as in Infusoria, &c. The special 

 nucleus gradually assumes an ellipsoidal shape, the proto- 



' SB. Ni/jlrrrkciv. 0,:s. Katur-v. U<-:ik. Bonn. Mav h. 1^79. 



