ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 121 



it is got rid of completely or almost completely by egg-laying ; it is 

 absent in the yoiiug spider unless some of the yolk remains ; it does 

 not reappear till the gonads develop. It is a complex hteraolytic agent. 

 It is present also in some Theridiidpe. In the eggs of Teiienaria atrica 

 there is a different toxin, which is to be classified with the simple 

 hiBmolysins. In a number of spiders the eggs have no hsemolytic sub- 

 stance or "complement" thereof. Extracts of Epeira which include 

 the ovary have a toxic effect. Besides causing general poisoning, a 

 subcutaneous injection of arachnolysin has marked local effects, especially 

 oedema and digestion of the tissues. 



Some ova have a " complement " with hasmolytic action, e.g. Meta 

 segmentata and Tetragnaiha moniana. The effect is toxic, but irregular. 

 The "complements" are nearly related to arachnolysin. There are 

 great specific differences. In Tegenaria atrica the eggs are hemolytic 

 ■and very toxic ; in T. parietina they are non-hremolytic and non-toxic. 

 The poison of T. atrica differs from arachnolysin. 



In spiders the poison of the chelicerfc is not htemolytic. It has 

 little action on Vertebrates, but a strong action on Arthropods (strikingly 

 on the crayfish). There is no relation as yet known between the poison 

 of the chelicera3 and that of the eggs. The blood of spiders has an 

 anti-toxic action on the poison of the same species. 



Notes on Parasitic Mites.* — Stanley Hirst deals with some species 

 of Acari parasitic on mammals and birds in Great Britain, several being 

 new to the British Fauna. He also describes two new African mites of 

 the family Gamasidffi — Haemogamasus liberiensis sp. n. from 3Ii/s trivir- 

 gatus and Haemolselaps (.') capensis sp. n. from Georychus hottentotus. 



«• Crustacea. 



Reproduction in Spiny Lobster.t — Bennet M. Allen, in the course 

 •of some notes on PanuUrus inierruptus, the spiny lobster of the 

 Californian coast, refers to the very small coral-red eggs which are 

 attached to the setffi of the pleopods. A careful estimate of the number 

 of eggs carried by the l-i-in. female showed it to be approximately half 

 a million. Fertilization, or, as the author says, insemination (which 

 does not seem strictly correct), " takes place from a putty-like mass of 

 •sperm material placed upon the ventral surface of the female's thorax 

 between the last three pairs of appendages. This mass contaius con- 

 torted tubular cavities in which the spermatozoa lie. It is at first white 

 and soft, but in a short time turns black and becomes hard. It comes 

 to resemble whalebone in consistency." 



Gammarid Studies. | — (harles Chilton descril)es Orchestia miranda 

 sp. n., from New Zealand, differing from the common 0. cliilienm, inas- 

 much as the largest males have the meral and carpal joints of the last 



* Journ. Zool. Research, i. (1916) pp. 59-81 (14 figs.). 



t Univ. California Publications (Zool.) xvi. (1916) pp. 139-52 (2 figs.). 



X Trans. New Zealand Inst., xlviii. (1916) pp. 354-9 (6 figs.). 



