ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 587 



cocaine (xoVo)' au d in de-oxygenated sea-water. They contract but do 

 not close in diluted sea-water and at temperatures higher than normal 

 (:->5° to 45° C). They remain open in currents of sea-water, and their 

 closure is inhibited by solutions of cocaine ( t ^ 1J q) and of atropine 

 (tfos)' an d hi fresh-water. They are apparently uninfluenced by low 

 temperatures, by weak solutions of cocaine (^tyoir), and of atropine 

 (twodOj an d by light. The ostia close on injury to neighbouring parts, 

 in solutions of ether (0 ■ 5 p.c), chloroform (0 ' 5 p.c), strychnine (nriWu)' 

 and cocaine (toVtj)- They open in solutions of cocaine (y^o^)* an ^ °f 

 atropine (xo l oo0> i n dilute sea-water, de-oxygenated sea-water, and warm 

 sea-water (85° C.) They are apparently unaffected by mechanical stimu- 

 lation, except injury, by low temperature, and by light. The choanocyte 

 currents cease in solutions of ether (0*5 p.c), and of chloroform (0*5 p.c), 

 in diluted sea-water, and at high temperatures (40° to 45° C). They 

 become slow at low temperatures (9° to 10° 0.), and fast in solutions of 

 strychnine ( T 5th)o)- ^ n de-oxygenated water they first become fast and 

 then cease. 



The flesh of Stylotella is capable of contraction, but such contraction 

 gives the sponge only a shrivelled appearance, without changing its 

 general form. The currents in Stylotella are constant in direction and 

 give no evidence of reversal. They are controlled by the ostial and 

 oscular sphincters. They produce a pressure equivalent to 3 ' 5 to 4 mm. 

 of water. The pressure necessary to break through the closed ostia is 

 10 to 15 mm. of water, and through the closed oscula somewhat more. 

 The reactive organs or Stylotella, the ostia, the oscula, the flesh, and the 

 choanocytes, are all more or less independent of one another, and their 

 action is changed by direct stimulation. In the ostia, oscula, and flesh 

 contraction is accomplished by spindle-shaped cells, the myocytes, which 

 resemble primitive smooth muscle-fibres. The body of Stylotella is 

 almost without transmission, and such transmission as is present is so 

 sluggish in character and so slight in range as to resemble transmission 

 in muscles and not in nerves. It is probable that Stylotella possesses no 

 organs that can reasonably be called nervous. The nervous and muscular 

 systems of Metazoa were not differentiated simultaneously (Kleinenberg, 

 O. and R. Hertwig), nor independently (Clans, Chun), but muscles, 

 independent effectors, as represented by the sphincters of sponges, were 

 the first of the neuro-muscular organs to appear, and these formed 

 centres around which the first truly nervous organs, receptors, in the 

 form of sense-cells, developed, giving rise to a condition such as is seen 

 in the Coelenterates to-day. To this receptor-effector system as seen in 

 modern Coelenterates was added in the higher Metazoa the adjuster or 

 central organ, thus completing the essential parts of the neuro-muscular 

 mechanism as seen in the higher Metazoa. 



Fresh-water Sponges from the Philippines and Australia. * — 

 Nelson Annandale describes Spongilla sceptrioides Haswell (New South 

 Wales and Queensland), a close ally of S. lacustris, and two new species, 

 S. philippe/isis (Philippines), and S. dementis (Philippines). 



* Proo. U.S.Nat. Museum, xxxvi. (1909) pp. 627-32 (4 figs). 



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