MILK. 



-..1 



As milk U the food of the young being amongst the Mammalia for 

 a period of several months, it must contain all the elements necessary 

 to the nutrition of the animal body. Dr. Prout therefore proposed to 

 classify all food according to the constituents of milk : 



1. Aqueous foods, represented by water. 



2. Albuminous foods, represented by the caseiue. 



3. Oleaginous foods, represented by the butter. 



4. Saccharine foods, represented by the sugar. 



The ashes also represent the inorgnnic constituents of the food of 

 all animals. [Kooi>.] The ashes in the milk of a cow examined by 

 Haidlen contained in 1000 parts: 



Phosphate of Lime . . 

 Phosphate of Magnesia . 

 Phosphate of Peroxide of Iron 

 Chloride of Potassium . 

 Chloride of Sodium . 

 Soda 



2-31 

 0-42 

 0-07 

 1-44 

 0-21 

 0-42 



4-90 



Tcr cent. 



47-1 

 8-6 

 1-4 



29-4 

 4-9 

 8-6 



1000 



The characters of the milk in the mammary gland, and the mode 

 of its secretion will be found under the article MAMMARY GLAXDS. 



Under the microscope fresh milk appears as a clear fluid in which 

 fat-globules, the so-called milk-globule*, are suspended as in an 

 emulsion. These globules differ very considerably in size ; the majority 

 hare a diameter of from 0-0012'" to 0-0018'", and although they are 

 rarely found to measure 0-0038'" in fresh milk, Henle states that he 

 has found them to be 0-014'", and according to Raspail and Donno*, 

 they are somtimes eren 0-044'". Although the milk-globules, without 

 the addition of a re-agent, exhibit no trace of an investing membrane, 

 its existence may readily be proved in two different ways. The 

 first is the addition of acetic acid, which causes these globules to 

 assume a variety of irregular forms which they would not if they were 

 simply globules of fat. The second way is to add a little ether to 

 milk, when it will be found that the ether will not dissolve up the milk- 

 globules which it would were these simple globules of oily matter. 



The milk immediately after delivery differs from milk that u 

 drawn subsequently. It has received the name of colosteum. On 

 examining colosteum under the microscope a very large number of 

 fat-globules are seen, some of which are larger than those that occur 

 in ordinary milk, and these are observed frequently clinging to each 

 other; besides these there are granulated, yellow, roundish corpuscles, 

 larger than the milk-globules, which appear to be composed of very 

 minute fat-vesicles. Their diameter varies according to Uenle from 

 (HXKJS'" to 0-0232'", but may are considered to be about 0-0111'". 

 The fat-granules of thee bodies are more easily dissolved by ether 

 than those of the milk-globules. Acetic ncid and potash dissolve the 

 p-anular combining substance, and scatter the fat-globules. From 

 these facts it would appear that the colostcum-corpuscles are very 

 small fat-globules imbedded in an albuminous substance. There is no 

 appearance of a nucleus or an investing membrane. These molecules 

 as a rule disappear the third or fourth day after delivery, although 

 they have been found as late as the twentieth day. They frequently 

 re-appear in the milk when any disease in the system supervenes. 

 Although there can be no doubt that the nature of the food affects the 

 composition of the milk, it has not yet been shown in what manner 

 this affects the particular constituents of the milk ; from experiments 

 made on dogs it would appear that when fed on vegetable diet their 

 milk was richer in butter and sugar, whilst the solid constituents are 

 generally augmented on a mixed animal and vegetable diet. Fat 

 food increases the quantity of butter. Plajfair found the butter of 

 cow's milk increased during stall feeding, and diminished when the 

 animals were kept out in the fields. Cows fed on bay that has been 

 cut and collected in a dry summer yield a richer milk, than when fed 

 on hay which has been cut in a wet season. 



Ferrier found, from a series of rx|x-rim< nt* on a suckling woman, 

 that the milk undergoes gradual changes dining lactation. While the 

 quantity of butter remained the same through the whole period, it 



was found that the caseine increased as the child became developed. 

 The sugar of milk diminished and the salts increased during the same 

 period. 



Various instruments have been invented for testing the purity of 

 milk, especially that of the cow. These instruments are called Oalacto- 

 scopes, or Oalactometers. [OJLLACTOMETER, in ARTS AND S-. . 1 nv.l 



MILK-THISTU:. [Slum:*.] 



MI I.K-WOKT. [POLYC.AI A. ] 



MILLEFOIL. [ACHIU.EA.] 



MILLEPO'RID.*. In the Linnsoan ' System* Natunc ' the genus 

 itilUpora included fourteen species of solid corals perforated with 

 conical non-lamelliferous pores. Several of them have been taken as 

 types of new genera or sub-genera, and, according to the general 

 practice of modern zoology, the Linnicm genus is transformed into 

 a great family. Lamarck (' Auimaux sans Vertebres ') places many 

 of the Millepores in his fourth section of Polyparia, the foraminated 

 corals, with Catenipora and Tubipora, which belong to other groups. 

 The Milleporida form a distinct order in the Foraminated Palyptaria 

 of Lamouroux (' Expos. Method.'), and include no less than eighteen 

 genera, namely : 



Orulita, Jletepora, Ltmulita, Orbulitet, Occltaria, Mcloberia, Eudca, 

 Alrcolita, Theonea, Ckryaaora, MMcpora, Terebtltaria, Spiropora, 

 Idmonea. (Diitichopora, JIurnrra, Knuauterna, and Tileria are in- 

 cluded among Millcpoi-idte in the table, but not in the body of the 

 work.) 



Lamouroux deSnes the MMeporida thus : Polyparia, stony, poly- 

 morphous, solid, internally compact; cells very small or porifrin, 

 scattered or in series, never lamelliferoua, though the parietes are 

 sometimes lightly striated. 



De Blainville collects the Mtileporidce into groups according to the 

 form of the cells in the coral, and defines the family by characters 

 drawn both from the animal and the stony support. 



Animals in general very slender, and provided with n single circle 

 of slender tentacula ; cells sometimes of considerable size, but always 

 without lamella) or striio within or without the tubes ; polyparium 

 fixed, varying in shape. Retrenching from the group the palmated 

 kinds (to form the genus Palmipora among tlr) Madrtphyllwca), -there 

 remain, according to De Blainville, twenty-three genera, which are 

 thus arranged : 



1. Cells polygonal, often rather large Favoti/et (Sanomia), Alrco- 

 litet, Aptmderia, T/teonca, J'tlagia, Tci-ebcllaria, Polytrema, Prmdipora, 

 Lichtnopora. 



2. Cells round, very fine, poriform, immersed Orbiculita, tfargi- 

 nopora, Stromatopora, Tilcsia, Spinopora, Ckrytaora, Ceriopora, 

 Datichopora, llcteropora. 



3. Cells round, more or lees tubular Ptutulopora, Zforncra, 

 Idmonea, Cricopora. 



The following arc the principal characters of these genera : 



SI. Cells Polygonal. 



Farotitft. Animals unknown ; cells prismatic, contiguous vertical, 

 or diverging, the parietes pierced with pores, the cavity divided by 

 transverse septa; polyparium branched or massive, sometimes 

 baaaltiform. 



It is a genus of Lamarck. Qoldfuss added to the knowledge of its 

 structure, but changed its name to C'alamopora. De Itlainville thinks 

 Kunomin of Lamouroux may be included in it, but the descriptions 

 are unlike. Ehrenberg places it near Attraa, in the family of Madrt- 

 phyllitr.a, and we think with reason. 



The I'nrusitet are only known in a fossil state, and, we believe, only 

 in strata of the Transition and Carboniferous eras, in the former of 

 which they are specially abundant, in the Eifel, Siluria, at Dudley, &c. 



P. Gothtandiea (Qoldfuss, tab. 20, f. 3) is a favourable example. (See 

 figures on the next column.) 



/.'uiiomio. Animals unknown ; cell* tubular, long, parallel, inter- 

 nally sulcated longitudinally, and transversely annulatcd ; the parietes 

 thick and solid. (Lamouroux, ' Expos. Method.') 



The only species, E. railiata, is fossil in Oolitic series of Caen. 



Alrealila. Animals unknown; cells short, tubular, prismatic, 

 alveoliform, the parietes thin ; polyparium furined into reticulated 

 layers, enveloping each other. 



It is a genus of Lamarck, subsequently, but without sufficient reason, 

 reunited by Qoldfuss to Faronten, under the name of t'alamopora. 



Two living species and a few fossil*, chiefly from the Tertiary series 

 of Dax. De Blainville includes in the genus (not correctly) many of 

 the C'alamopora of Uoldfuss which are to be ranked as Favorite*. 



Prondipora, Animals unknown ; cells unequal, subpolygonal, 

 accumulated irregularly, prominent only on the external surface of a 

 finely branched polyparium, which is fixed, arborescent, variously 

 reticulated, and longitudinally striated on the non-celluliferous face. 



One of the species is ranked as a Kettpora by Lamarck. Lamouroux 

 (following Tilesius) calls it Krutcntterna. The species are recent in 

 the seas of Kamtchatka and the Mediterranean. Ex. F. re'iculata, 

 (Blainv., pi. 69, f. 1. 



lAchenopora, Animals unknown ; cells rather large, poriform or 

 null-tubular, nub-polygonal, accumulated and scattered on the interior 

 surface of a fixed orbicular cupuliform polyparium, which is quite 

 smooth externally. 



