Botany at the British Association. 299 



pointed out that they were undoubtedly concretions largely 

 composed of Ca CO3, varying in size, and often surrounded by 

 •coal. As a rule the plants in two neighbouring balls are 

 disconnected fragments, but in some cases the same plant 

 continues in two nodules. This suggests that the concretions 

 containing the plant tissues were formed in the place in which 

 we now find them. She supported the view advanced by Binney 

 that the constant association with the roof nodules containing 

 marine shells suggests that the infiltration of sea-water and 

 <;arbonate was necessary for the formation of true ' coal balls.* 

 Mr. Lomax made the not very probable suggestion that coal 

 balls were water worn, and had been carried to their present 

 position by strong currents of water. He admitted at the outset 

 that Dr. Stopes had taken the wind out of his sails. However 

 formed, a study of their contents has helped forward palaeo- 

 botany at a rapid rate during recent years. There is obviously 

 much valuable work waiting to be done around our own doors. 

 Saturday was a busy morning. Mr. Gallagher opened with 

 an account of the ' Root Anatomy of the Cupuliferae and of the 

 Meliaceas.' He found two distinct types of rootlets in our 

 native Cupuliferae. {(i) Rootlets free from fungus, these 

 possessing- a root cap, root hairs, definite hypoderm, and cortex 

 of upwards of twenty concentric layers are present ; these are 

 clearly not roots of extension and fixation alone, they are also 

 absorptive, as shown by the well-developed root hairs. (6) 

 Rootlets bearing an exotrophic mycorhiza, in these root cap, 

 root hairs, and hypoderm are absent ; there are not half a dozen 

 •concentric layers in the cortex, and the rootlets are much 

 shorter than in [a). Culture of the mycorhiza on various media 

 were made, but no fructification could be obtained. Dr. 

 Blakeslee gave an account of ' Zygospore Germinations in the 

 Mucorineae,' illustrated by many interesting cultures. All were 

 glad to see Prof. E. C. Jeff"rey, whose anatomical work has won 

 general admiration. He is now studying the anatomy of 

 Mesozoic plants, and gave some results of his work on the 

 ' Structure and wound reactions of the genus Brachyphylliim,' 

 Prof. Weiss described a ' Stigmaria of unusual type,' found in 

 a nodule from the Halifax hard bed of the lower coal measures 

 It differs from most specimens of stigmaria in the considerable 

 amount of primary wood which was centripetal in its develop- 

 ment. Prof. Bottomley had been carrying out experiments on 

 the ' Cross-innoculation of Leguminosae and other root-nodule 

 bearing plants,' and showed that, provided the specific organism 



1906 September i. 



