Degenerative Changes in Sensory End Organs of Muscles. 61 



soon as, with the increase in size and complexity of the spore-bearing 

 plant, a vegetation capable of affording shade came into existence, 

 the conditions suitable for the persistence of the more primitive, 

 alga-like, sexual stage in the life history would be present. The 

 latter has, of course, also been modified in various ways. 



In the concluding portion of this paper, the theories of antithetic 

 and homologous alternation are compared by considering the expla- 

 nations they afford of the facts. The general conclusion reached is 

 that, while both afford a possible explanation of the facts of alter- 

 nation in archegoniate plants, any evidence which would render one 

 or the other untenable is wanting. The reasons on which either is 

 considered more probable depend on the views held as to the lines 

 of descent which have been followed, and the degree to which the 

 different groups of archegoniate plants have had a common origin, 

 or represent actual steps in the process of evolution of the sporo- 

 phyte. Under these circumstances the question must be regarded 

 as an open one until the available lines of evidence have been more 

 fully investigated. 



I am especially indebted to Dr. Scott and Professor Bower for 

 their assistance and advice ; the work was commenced in the Jodrell 

 Laboratory of the Royal Gardens, Kew, and subsequently carried on 

 in the Botanical Laboratory of the University of Glasgow. 



" Experimental Observations on the early Degenerative Changes 

 in the Sensory End Organs of Muscles." By F. E. BATTEN, 

 M.D. Communicated by Professor VICTOR HORSLEY, F.R.S. 

 Received February 17, Read March 3, 1898. 



(Abstract.) 



The experiments described in the following paper were under- 

 taken in order to show, firstly, that degeneration occurred in the 

 first place in that part of the neuron most remote from the cell, and 

 secondly, to reproduce within the muscle-spindle, if possible, certain 

 changes which had been shown by the author to be present in the 

 case of tabes dorsalis in man. 



The method of experiment was as follows: Dogs were selected, 

 and the mixed roots of the 5th cervical to the 1st dorsal inclusive 

 were divided, and the animals killed at the following periods after 

 section of the nerve, viz., 24, 48, 72, 96, 120 hours, and 7 and 14 

 days. 



From the biceps muscle after being treated by Sihler's method 

 mscle-spindles were teased out ; some of these were mounted with- 

 >ut further staining, others were treated by Marchi's method, others. 



)re stained by the Marchi-Pal method, 



