Dr. D. Ellis — A Jurassic Fossil Fungus. 107 



fragment showing traces of animal cells (a), and also a few hyphae 

 of some unknown fungus (b). Again, in others inside similar organic 

 fragments structures like those represented in the Text-figure and 

 in PI. VII, Fig. 5 were met with. These are obviously the remains 

 of some animal cells, although in this condition it is impossible to 

 specify any further with regard to their nature. The point of the 

 matter lies in this, that these organic fragments from Dunliath 

 contain the remains of both animal cells and fungal threads, both 

 very incomplete and very indefinite: in the Frodingham Ironstone 

 the disruption of the animal cells has been complete, whilst the 

 fungus, thanks to its protective covering, has been particularly well 

 preserved. 



4. Doubts arising from the fact that the threads and vesicles were 

 found in material known to have suffered decomposition in sea-ivater. — 

 Whilst it is true that no fossil fungi have so far been found of 

 which it could be definitely stated that they had effected decom- 

 position in salt water, the reason for this does not lie in the fact 

 that there is anything inherently impossible in the idea, for that 

 would imply that decomposition of organic matter cannot take place 

 in salt water, which is contrary to experience. It is true that the 

 vast bulk of marine decomposition is due to the activity of bacteria, 

 but even in this field a large proportion of the organisms which carry 

 on this decomposition belong to the sulphur bacteria, several species 

 of which group are composed of long threads, thus approximating in 

 their habits to the threads of which the aquatic fungi are composed. 

 In the artificial cultivation of many of the thread-forming sulphur 

 bacteria success attends the attempt only if sea water instead of 

 fresh water be employed. A still more powerful argument is the 

 fact that in the cultivation of some of the Saprolegnias, a group of 

 phyoomycetous fungi, the use of sea water is recommended in making 

 up the nutrient medium. So that even in the case of modern plants 

 of the same group we meet with fungal decomposition under marine 

 conditions. Anyone who has studied the shores of Denmark can 

 satisfy himself of the extent to which marine decomposition can 

 operate in the scavenger work of Nature. The shallow Jurassic seas 

 must have had huge shallow lagoons in which of necessity scavenger 

 work on a large scale must have been in operation. It would be an 

 extremely rash statement to assert even apart from our experience 

 of modern fungi that no thread fungi could have contributed to this 

 work. For even if such fungi did not exist at the present day, there 

 are so many closely allied forms that effect decomposition in salt 

 water that marine fungi in a fossil form would not have been 

 a matter for surprise. 



Conclusion. — The study of the tubes and vesicles classed under 

 Phy corny cites Frodinghamii had revealed their organic nature by the 

 closeness with which their structures followed those of modern fungi. 

 The resemblances extended even to minute points of structure, and 

 were so great that from a biological standpoint no doubts were enter- 

 tained as to the fact that we were dealing with fossil fungi allied to 

 the modern Phycomyeetes. It remained to inquire whether any 

 positive evidence could be adduced, or any facts brought forward on 



