110 Mr. Goumje on (he Fossil Plants in the Glasgow Geological Museum. 



this hollow structure of the leaves is beautifully seen. We possess a 

 fine specimen of a branch, ten feet in length, and a good specimen of 

 the central dome may be seen in the Andersonian Museum. After 

 quoting a description of the structure of the Stigmaria from the " Fossil 

 Flora," this part of the paper was concluded with the observation, that 

 as no plants of tlie present day have such a structure, Stigmaria repre- 

 sents a race now altogether extinct. 



An important point of interest is the climate and atmosphere of the 

 carboniferous epoch. That the immense plants of the coal lived and 

 flourished during the prevalence of a high temperature, equal to, or 

 perhaps greater than that of our torrid zone, is now generally believed. 

 Brongniart has suggested that during the same period the atmosphere 

 contained a much larger proportion of carbonic acid gas than it does 

 now, which supplying abundance of food to the leaves of these plants, 

 would greatly favour their development, and cause a rapid growth. 



It has also been conjectured that the gigantic lizards, batrachian 

 reptiles, and marsupial animals of former days may have been able to 

 exist during this state of things, — that the horned iguanodon or long- 

 necked plesiosaurus might inhale such an atmosphere with zest, and 

 that the megalichthys, with its armorial covering of burnished enamel, 

 may possibly have delighted to roam in aerated waters ! Instead of 

 indulging in theories which, however ingenious, seem to be somewhat 

 extravagant and improbable, we would rather refer the phenomena 

 observable in the coal formation to causes even now in operation, and 

 agree with our President, Dr. Thomson, that " it is very hazardous to 

 draw such conclusions, from the number and appearance of these 

 plants, which, for anything we know to the contrary, may have been 

 adapted for a colder climate, although analogous in some respects to 

 those at present inhabiting torrid regions."* 



The tropical flora of the present day, in many places, such as 

 Southern India, Java, or Guiana, is probably more luxuriant than was 

 that of the coal. Immense cities exist in Central America which have 

 once been inhabited by races of people acquainted with the arts of 

 civilized life, but which are now desolate, and buried in immense 

 forests, often so thick and impervious that the light of day can hardly 

 penetrate the mass of foliage. A rank and powerful vegetation has 

 invaded the homes, altars, and palaces of this ancient people. Their 

 immense and often beautifully sculptured idols or monuments are 

 overturned by the expansion of roots, and bound down by enormous 

 creeping and twining stems ; and Mr. Stephens, in his intensely 

 interesting account of them, tells us that the vegetative force has 

 sometimes been so great as to lift large masses of masonry out of the 

 earth, and almost heave them up in the air. Luxuriant and vigorous 

 vegetation like this does not arise from heat alone, but from the com- 



* Thomson** Outlines of Geology, vol. II. p. 260. 



