摘要:

The functional morphology of the alimentary canal ofMarinogammarus obtusatusDahl is described, with particular reference to the proventriculus and the digestive gland. The proventriculus is a device (1) for the mastication of food, (2) for retaining it while it is being broken up and acted upon by enzymes and (3) in which provision must be made to convey enzymes forward into the cardiac region and digested food backwards to the digestive gland. Finally, there must be a valvular device to direct undigested food past the ducts leading to the digestive gland and into the intestine.The proventriculus of M. obtusutw. is compared with that of mysids and isopods and it is concluded that modifications of the fore‐gut in various lacostracan groups are likely to be adaptations to diflerences in food and feeding habitsThere is no clear functional distinction between the so‐called secretory and reserve cells of the digestive gland, both of which secrete enzymes, absorb and store f

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1964.tb03879.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The alimentary canal ofOrchestia gammarellaPallas consists of the foregut, midgut and hindgut. It has been found that the ventral hepatopancreas, arising from the anterior part of the midgut, secretes the different digestive enzymes.For the determination of optimum pH for the activity of Merent carbohydrases, Somogyi's blood sugar method has been employed and it has been investigated that the optimum pH for the activity of caecal invertase, glycogenase, amylase and amygdalinase lies between 5.6 and 6.1.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1964.tb03880.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

A study of the structure and innervation of dolphin skin from different sites is presented and the findings evaluated in the light of behavioural studies.The suggestion is made that the skin plays an important part in the economy of the animal by (1) insuring fully laminar flow at high speed and (2) the detection and location of low‐frequency vibrations of focal origi

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1964.tb03881.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The lateral lobes (processūTs glandis) of the penis are reviewed for all extant rhinoceros genera. Previous accounts of these structures are confirmed forRhinoceros unicornisand forDiecros bicornisand a first description of them is given forCeratotherium simum.The morphological nature of these external penile features (as extensions of the corpus cavernosum) is established and their taxonomic value is considered. Observations are made upon the penis constitution ofDicerosand ofCeratotherium

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1964.tb03882.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The morphology of the spermathecal system of a new genus of Eudrilid earthworm from south‐eastern Ghana is described and functional details are discussed. Interconnections are traced between the spermathecal and female systems and the mechanism is described which ensures that fertilization takes place in the middle region of the oviduct at a time other than during copulation. It is pointed out that the spermathecal system is probably mesodermal in origin instead of ectodermal which is usual in other families of Oligochaeta. The new genus is characterized by the presence of both an oesophageal and a series of intestinal gizzards and by paired oesophageal glands arising in segmentxiv.Three species are described and may be distinguished by several characters. The more readily evident external differences are: the number of segments, form of the clitellum, position of the spermathecal pore and the presence (in one species) of copulatory appendages. The similarities and affinities of the genus withHyperiodrilusBeddard are discussed. Itis admitted that it is expedient to accept the criteria of the current classification of the Eudrilidae until a full revision of the family can be carried out, so making necessary the erection of this new genus for the three species here described. A table is provided listing the distinguishing characters of the new specie

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1964.tb03883.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

A and B. The behaviour of eight rhesus monkeys during the first six months of life was studied. The animals were brought up by their natural mothers living in captivity in small social groups containing one adult male and three or four adult females.C (i). Three births were witnessed. The placenta was not eaten in some cases.C (ii). Many of the mothers held their babies in abnormal positions immediately after birth. They were often held so tightly that they could not turn their heads to gain the nipple.D (i)The normal ventro‐ventral nursing position is described.D (ii)The methods by which the infant finds the nipple are described. The time spent by the infant on the nipple with its eyes open rose to a peak of 35 per cent in the third week, and then declined (Fig. 1). Only a small proportion of the time spent on the nipple is occupied by sucking.D (iii). A nipple preference is established during the first few weeks. This may not be a sucking preference.D (iv). The proportion of time in which the infant's eyes were closed fell from 70 per cent in week 1 to about 25 per cent after five weeks, and then more slowly (Fig. 2). The proportion of time on the mother with the eyes open but not attached to the nipple rose to a peak of 22 per cent in weeks 7/8 (Fig. 3).D (v). The way in which the mother carried the baby during locomotion is described. Riding on the mother's back was not common in our colony.D (vi). Some observations on the development of eye‐hand‐mouth coordination are described. The ages at which certain criteria of achievement were reached are given in Table 3.D (vii). The initiative for the first separation between mother and infant comes sometimes from the mother, sometimes from the infant.D (viii). The proportion of time spent off the mother rose t o about 60 per cent after 16 weeks (Fig. 4).D (ix). The ages at which certain criteria of achievement were attained are given in Table 4.D (x). The manner in which the infant follows its mother is described.D (xi). As the infants get older, the length of the periods which they spend off their mother increases (Fig. 5). After the sixth week the infant spends a considerable proportion of its time more than two feet from its mother (Figs. 6, 7&8).D (xii). The relative roles of infant and mother in increasing and decreasing the distance between them are shown in Figs. 9 and 10.D (xiii).The manner in which the mother protects and grooms the infant is describedD (xiv). The development of independent feeding is described. (Fig. 11). She also shows various types of “affectionate” behaviour without obvious function.D (xv). As the infant gets older, there are a number of contexts in which its behaviour is not reciprocal to that of the mother. Mother‐infant incompatibility arises in the The development of independent feeding is described contexts of sucking, carrying, feeding, explorati

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1964.tb03884.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1964.tb03885.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY