96 SUMMAKY OF CURKEXT RESEARCHES RELATING TO 



in preparations, than the male gametocyte. The latter has a limited 

 affinity for stain, and is smaller than the female. The pathogenicity 

 of this parasite has not been established. 



Life-history of Spirochseta pallida. — J. E. R. McDonagh* has 

 investigated the phases of this parasite by studying syphilitic glands and 

 skin lesions by means of the borax-methylen-blue film method, as well 

 as by the examination of fixed specimens. He gives the life-history as 

 follows : A small flagellate sporozoite enters a mononuclear cell, becomes 

 encysted and grows. It may develop either into an irregular coil from 

 which spirochfetes (male gametes) arise, or into a number of pear-shaped 

 bodies from which macrogametes are formed. The author has not 

 observed the act of fertilization, but describes the division of the zygote 

 and the ultimate liberation of the sporozoites. He refers also to an 

 asexual cycle, similar to that observed in the Flagellata. These observa- 

 tions indicate that the parasite belongs to the sporozoa, and the name 

 Leucocytozoon syphilis is suggested. Probably infection is conveyed by 

 the sporozoite and not by the Spirochaste. In a later communication,! 

 the author gives a schematic representation of this life-history, which 

 appears to resemble very closely that of the malarial parasite. 



E. H. Ross X has examined material from chancres and secondary 

 syphiHdes in 143 cases by means of the jelly method. He interprets 

 his observations as follows : small extracellular, round or pear-shaped 

 bodies become included within the cytoplasm of leucocytes and endo- 

 thelial cells, there to become encysted and to grow. The chromatin 

 undergoes subdivision. In the full-grown individual each chromatin 

 mass resembles one of the free pear-shaped bodies. In some instances 

 the chromatin develops instead into minute spirochaete-like tails, which 

 are extruded when the inclusion bursts. The author refers to the 

 homologies between these phases and the intracellular parasites of 

 guinea-pigs and eartliworms in different stages of their life-history, and 

 suggests that the Spirochaete form may be a microgamete and the pear- 

 shaped body a macrogamete. Conjugation has not been observed, but 

 the appearance of certain cells found in the deeper layers of secondary 

 syphiiides suggests that the parasite is a protozoon having a cycle of 

 sporogony. Control examinations of material from non-syphilitic 

 persons failed to show any of these forms. 



E. Jennings § and S. R. Moolgavkar,|| working with the jelly method, 

 have similarly found extracellular and intracellular forms of the parasite 

 in material obtained from chancres and sores. 



Molluscum contagiosum.^— R. Campanahas obtained cultures of the 

 parasite responsi))le for this disease by transferring material, obtained 

 under aseptic precautions from a patient, to the surface of a culture 



* Proc. Roy. Soc Med., Sect. Derm., vi. (1912) pp. 8-15. 



t Lancet, 1912, ii. p. 1G51. 



: Brit. Med. Journ., 1912, ii. pp. 1651-4. 



§ Brit. Med, Journ., 1912, ii. p. 1655. 



II Brit. Med. Journ.,, 1912, ii. pp. 1655-6. 



il Centralbl. Bakt., He Abt. Orig., Ixv. (1912) pp. 458-66. 



