445 
the literature of the muscle controversy explains these discrepancies by 
showing that each observer has figured his specimens in different states 
of extension. With slight contraction Flögel’s granules disappear, then 
Dobie’s globules; finally in completed contraction the two heads of 
adjacent sarcous elements come together and the fibril is momentarily 
homogeneous, the former complexity reappearing on extension. Such 
phenomena can readily be explained, if we regard the doubly refracting 
portions as aggregation granules whose union and separation is ren- 
dered linear by the bounding surface of the fibril, rendered symmetri- 
cal by the fixed points of Krause’s membrane, and rhythmic by re- 
gularly applied nervous stimulus, the attractions and surface tensions 
of these globules and elongated masses thus effecting a contraction of the 
muscle, the elasticity and capillarity of the fibrillar sheath acting for 
its extension. The sum of the tendencies of the innumerable elongated 
aggregation masses of a muscular fibre towards the spherical form at 
once accounts for the shortening and broadening of the muscle and the 
overcoming of resistance. This view agrees too with what recent re- 
searches have revealed as to the development of muscular substance and 
with Strasburger’s observations on the striated border of some active 
Amoebae. Suchan hypothesis has innumerable corollaries, but it is 
sufficient for the present to point out its increased applicability to the 
cell cycle, since the increase and decrease of cellular activity upon 
which that depends should be largely associated with corresponding 
variation in aggregation. 
Zoological Laboratory, School of medicine, Edinburgh, 6. June 1883. 
II Mittheilungen aus Museen, Instituten etc. 
1. Zoological Society of London. 
19th June, 1883. — The Secretary read a report on the addition, 
that had been made to the Society's Menagerie during the month of Mays 
and called special attention to a fine example of the Surucucu or Bush-maste, 
Snake of South America (Lackesis mutus), presented by H. Y. Barkley, Esq.r 
of Pernambuco, on the 22nd of May. — The Secretary read an extract 
from a letter received from Mr. Albert A. C. Le Souéf, containing obser- 
vations on the coloration of the plumage of the Satin Bower-bird (Piilono- 
rhynchus holosericeus). — Prof. E. Ray Lankester, F.R.S., read a 
memoir on the muscular and endoskeletal systems of Limulus and Scorpio, 
drawn up by himself with the assistance of his two pupils, Mr. W. J. Bar- 
ham and Miss E. M. Beck. ‘These investigations seemed to confirm Prof. 
Lankester’s previously expressed views as to the near affinity of these two 
forms, hitherto usually referred to different classes of the Animal Kingdom, 
