蟑螂是一种为人所熟知,而亦为人所共恶之昆虫,其分布之广,遍及於吾人日常生活有关各场所。作者曾检查其阳胃,发现仅鞭毛虫一类,已达五种之多。为明了此类鞭毛虫之形态与构造,曾用特种染色术制成片子,详加观察,藉与寄生於人体内巳知之鞭毛虫比较,寻求其中关系,推断有无传播之可能。兹将研究结果,摘其大要,分述如下: 1.Rhizomastix gracilis Alexeieff.此虫於1911年,Alexeieff氏在蠑螈腸中首先发现,至1913年,Mackinnon氏於大蚊(Tipula)之幼虫肠中,亦会见到;惟在蟑螂所见者,尚属初次。其身体通常呈卵形或圆形,构造较为简单,一条较身体约 Cockroach is a well-known, but also a total of evil people insects, its wide distribution, throughout our daily life of the various places. The author has examined its Yang stomach, found only flagellate a class, has reached as many as five. In order to clarify the morphology and structure of such flagellates, it was made into a film by special dyeing technique, observed in detail and compared with the known flagellated parasites in the human body to find out the relationship between them and infer the possibility of their spread. The results, summarized in the following, are summarized as follows: 1. Rhizomastix gracilis Alexeieff. This insect was first discovered in 1917 by Alexeieff in the salamander intestine. By 1913, Mackinnon’s larvae of the Tipula Will see the intestine, but the cockroach saw, is still the first time. Its body is usually oval or round, the structure is relatively simple, a body about