共查询到20条相似文献,搜索用时 156 毫秒
1.
2.
蛇类半阴茎的形态特征在蛇类分类、进化和系统发育等研究中具有重要价值.本文介绍了一种改进的固定蛇类标本外翻半阴茎的制作方法. 相似文献
3.
4.
5.
虎斑颈槽蛇是中国数量较多、分布最广的蛇类之一,但一直被当作无毒蛇而忽视。为了使人们对虎斑颈槽蛇有一个全面、正确的认识,也为以后的相关研究奠定一定的理论基础,从虎斑颈槽蛇的分布,形态,生活习性以及毒腺的研究等方面加以综述。 相似文献
6.
7.
蛇是有多种经济用途的野生动物,近年来市场需求量越来越大,捕捉野生蛇类受到资源的限制,驯养蛇类已成为快速致富的重要途径。蛇类驯养成功的关键在于蛇园的拟态程度。目前我国多采用蛇房与蛇园分离的结构,这种结构虽然便于蛇类捕捉,但增加了投资,且与野生蛇类的生境结构有较大差别,不利于蛇的驯养。我们设计蛇房假山一体化结构的蛇园,很好地解决了上述问题,现介绍如下。1 蛇房假山一体化结构 蛇房假山一体化是将蛇房与假山建在一起。蛇房建在园内蛇的活动区,内部建造成蛇窝供蛇避暑、冬眠、休息及藏身。蛇房的外围堆垫土层,… 相似文献
8.
9.
10.
11.
Julia D. Harrison 《American anthropologist》2000,102(1):159-160
Oka: Behind the Barricades. 1998. 312 minutes. For more information contact the National Film Board of Canada, 3155 Côte de Lisse Rd., St. Laurent, Quebec H4N 2N4. Series of four videos:
Kanehsatake: 270 Years of Resistance. 1993. 120 minutes. Directed by Alanis Obomsawin .
Spudwrench: Kahnawake Man. 1997. 58 minutes. Directed by Alanis Obomsawin .
My Name is Kahentiiosta. 1995. 30 minutes. Directed by Alanis Obomsawin .
Acts of Defiance. 1992. 104 minutes. Directed by Alec MacLeod . 相似文献
Kanehsatake: 270 Years of Resistance. 1993. 120 minutes. Directed by Alanis Obomsawin .
Spudwrench: Kahnawake Man. 1997. 58 minutes. Directed by Alanis Obomsawin .
My Name is Kahentiiosta. 1995. 30 minutes. Directed by Alanis Obomsawin .
Acts of Defiance. 1992. 104 minutes. Directed by Alec MacLeod . 相似文献
12.
13.
14.
15.
16.
17.
J. H. Porter 《BMJ (Clinical research ed.)》1875,1(737):206-208
18.
19.
20.
When viewed by scanning electron microscopy (SEM), the spermatozoon of the phorid dipteran Megaselia scalaris appears threadlike, lacking distinct head and tail areas. These areas can be observed, however, in appropriately stained material. Measurements of Feulgen-stained material reveal average lengths of the head, tail, and total cell of 18.7, 128.7, and 147.4 μm, respectively. When tested for sulfhydryl and disulfide groups, the head displays only disulfide groups. Transmission electron microscopy (TEM) reveals 12 different regions: three (1–3) in the head, four (9–12) in the tail, and five (4–8) in a short zone of overlap between the head and tail. Most of the cell lies in regions 9 and 11 of the tail and 3 of the head, accounting for, respectively, 37.3%, 45.7%, and 11.2% of the total length. A tubelike acrosome indents the anterior end of the nucleus. The tail originates asymmetrically in relation to the long axis of the cell as a peglike structure associated with the dorsolateral region of the nucleus. No centriole is visible, and the nucleus has a notched appearance in longitudinal sections. Two mitochondrial derivatives and an axoneme displaying a 9+9+2 microtubule configuration and ATPase activity extend throughout most of the tail. In regions 9 and 10, an asymmetrically arranged accessory body is also present. Features having possible taxonomic utility include the asymmetrically arranged accessory body, the size and shape of the acrosome, and the notched appearance of the nucleus. The present report is apparently the first to describe the spermatozoon of a cyclorrhaphous dipteran which is not a member of the Schizophora. 相似文献