722 SUMMARY OF CUBRENT RESEARCHES RELATING TO 



The size and colour of tbe corpuscles of mosquito blood are so 

 different that no mistake could of course arise. 



As tbe result of more tban a hundred careful measurements be gives 

 tbe following sizes : — Human blood (after imbibition by tbe mosquito), 

 averages (red corpuscle), in dilute glycerine, 7* 4 /a or ^^^oo ii^cb ; in 

 80 per cent, alcohol, 6 • 9 yu, or ^o^o inch. Mosquito blood averages 

 in dilute glycerine, 1'8 fj. or y^g-g- inch ; in 80 per cent, alcohol, 

 1*4 fjL or Igloo inch. Dr. Curtman considers therefore that 

 another prop is thus taken from the value of circumstantial evidence 

 derived from suspicious stains in murder cases ; for even if stains 

 should be fully identified as derived from human blood, the accused 

 may plead that they were due to the agency of insects ; and a writer * 

 on this paper closes bis account with the remark, " Verily, the 

 criminal should dwell in the land of tbe mosquito." 



Later experiments on bed-bugs appear to show that the imbibed 

 human blood is destroyed far more rapidly in them than in tbe 

 mosquito. In one individual, after twelve hours not a trace of the 

 human blood-corpuscle could be detected. 



Salivary Globules.-j- — Prof. Strieker, of Vienna, by examination 

 of salivary globules under high powers (obj. No. X. of Krafft and 

 Seibert), has obtained the following results : — He cannot accept tbe 

 supj)osition of a so-called Brownian (molecular) movement in salivary 

 corpuscles. He has found the globules to consist of a complete, 

 distinctly visible network, Tbe granules, which have been seen under 

 low powers of the Microscope, appear on close inspection and care- 

 fully focussing to be thickened points of intersection of tbe threads 

 forming the reticulum. There is a permanent fluctuation of the 

 threads during the life of the corpuscle. By the action of concentrated 

 salt-solutions, the fluctuation ceases gradually and the reticular 

 arrangement disappears. 



B. INVERTEBRATA. 



Fossil Organisms in Meteorites.J — Dr. O. Hahn, who will be re- 

 membered for the part be took in the " Eozoon " controversy,§ claims to 

 have established the existence of fossil organisms in sections of meteo- 

 rites, and his views have been confirmed by Professor Karsten and 

 Dr. D. F. Weinland, the former of whom recognized vegetable forms, 

 while Dr. Hahn was only able to find animal organisms. To enable 

 a better judgment to be formed by the preparations made by Dr. Hahn, 

 32 photolithographic plates are given of 142 (transparent) sections. 



Dr. Weinland estimates that tliere are 50 various species of polypes, 

 crinoids, and algse in Dr. Hahn's preparations. They are united 

 by a siliceous material, and the most interesting feature is their dimi- 

 nutive size, tbe spicula of sponges, for instance, being indistinguish- 



* Louisville Med. Herald, ii. (1880) p. 323. 

 t 'Nature.' sxiv. (1881) p. 203. 



X Hahn, O., 'Die Meteorite (Chundrite) und ihre Organismen,' Tubingen, 

 1881. 



§ See this Journal, iii. (1880) p. 471. 



