728 5. Entwicklungslehre. 



1580) Brindley, H. H. (Cambridge University), Furt her Notes on the 

 procession of Cnethocampa pinivora. 



(Proc. Cambridge Philosoph. Soc. 15,6. p. 576—587. 2 plates. 1910.) 



Previous writers, including the autbor, have described the habits of the 

 larvae of this Procession Moth. The eggs are laid in September on the 

 leaves of Pinus pinaster, and the young larvae, offspring of one parent, con- 

 struct a silk nest in the branches, in wbich they pass the winter. In March 

 and April the larvae are found marching in Single file over tbe sand in wbich 

 the pines grow. Burrowing for pupation concludes the last procession. The 

 imagos hatch in August. The present paper describes observations on points 

 wbich previous observers had left undecided. One of the chief of these is 

 whether Fabre's Suggestion is correct that the procession of larvae finds its 

 way back to the nest tree by means of the thread secreted by each larva 

 as it goes. It was found that processions frequently break up into two or 

 more parties, and that stray larvae readily join a procession, so that there is 

 no probability that all the larvae of one procession usually belong to one nest. 

 Experiments with the thread showed that the leader disregarded threads 

 placed a cross the line of march, whether the thread was secreted by that 

 procession or by another. The observations thus gave a negative result. The 

 thread also does not seem to be of much importance in enabling the hinder 

 larvae to follow the leader. The sight of the larva in front is the chief 

 factor. When on the march the larvae frequently form a 'circulating mass', 

 in which the chain breaks up into a heap of larvae Walking over each other 

 and not progressing. Observations and experiments on the re-formation of the 

 procession from the 'circulating mass' showed that by no means always the 

 leader was the same as before, but the leader was the same more often than 

 would be accounted for by mere chance. 



Observations on the influence of light in directing the route of a proces- 

 sion gave negative results. The burying for pupation usually takes place 

 from a 'circulating mass'; a larva will completely bury itself in 10 — 40 mi- 

 nutes. Doncaster (Cambridge). 



1581) Johnson, M. E. , A Quantitative Study of the Development 

 of tbe Salpa Chain in Salpa fusiformis-runcinata. 



(Univ. of California Publ. in Zoölogy 6,7. 1910.) 



The subjects dealt with in this paper are (a) the species and its manner 

 of reproduction, (b) the form and structure of the chain, (c) the method fol- 

 lowed in taking measurements, (d) a discussion of conclusions. 



The chain of Salpa fusiformis-runcinata is made up of a series of blocks, 

 the zoöids of each block being of approximately the same size. On the oldest 

 blocks the most proximal zoöids are larger than the most distal ones; in the 

 youngest, the distal ones are larger than tbe proximal. A comparative study 

 of S. zonaria-cordiformis and S. cylindrica suggests that further investigation 

 may show the graph of tbe block to be a reliable species character. 



The periodicity occurring in the salpa chain may be a pheuomenon com- 

 parable with the grand period of growth and also with the length period of 

 the internodes, as defined by botanists. Pearl 's first law of growth finds 

 a parallel in the salpa chain, since the size of a zoöid is a function of its 

 Position in the block. Stevens (Bryn Mawr). 



1582) Brenchley, W. E., The influence of copper sulphate and 

 manganes sulphate upor the growth of barley. 



(Annais of Bot. 24,3 p. 571—583. 1910.)' 

 Die Arbeit versucht den Einfluß von Kupfer- und Mangansulfat auf 



