while this invention is satisfied by embodiments in many different forms , there is shown in the drawings and will herein be described in detail , the preferred embodiments of the invention , with the understanding that the present disclosure is to be considered as exemplary of the principles of the invention and is not intended to limit the invention to the embodiments illustrated . various other modifications will be apparent to and readily made by those skilled in the art without departing from the scope and spirit of the invention . the scope of the invention will be measured by the appended claims and their equivalents . fig1 illustrates a growth environment assembly 10 , comprising a vessel 12 , a closure 14 and a tubular membrane 16 . the vessel is preferably made from impact resistant plastic or glass which is gas impermeable , optically clear , non - toxic and inert with respect to the cells to be cultured . vessel 12 has a body 18 in which material is adapted to be held until such time as the same is withdrawn or dispensed . it is unimportant whether body 18 is made of a collapsible or no - collapsible material , such as metals , plastics or glass . as shown in fig1 vessel 12 includes a neck 22 to receive closure 14 . neck 22 is integral with the vessel and defines a cylindrical conduit having one end integral with the vessel and the other end defining an opening through which the cells and culture fluids may be introduced into the body of the vessel . neck 22 and closure 12 constitute one of a number of well known means for introducing materials such as mammalian cells and culture fluids into body 18 . as is conventionally know , closure 14 is removed from neck 22 to provide an opening through which cells and culturing fluids can be introduced into the vessel . the closure is subsequently remounted onto the neck to re - seal the vessel . as shown in fig2 and 3 , closure 14 has a top surface 24 , a bottom stop ledge 26 and an annular outer skirt 28 extending from the top surface to the bottom stop ledge . the annular outer skirt has an outer wall surface 30 and an inner wall surface 32 . the top surface of the closure further comprises entry port 34 and sampling port 36 . tubular membrane 16 extends from entry port 34 of the closure and into the vessel . as shown in fig4 tubular membrane 16 comprises an open end 38 , a closed end 40 and a hollow cavity 42 containing the means to distribute fluid substances . tubular membrane 16 comprises a sidewall 44 that extends from open end 38 to closed end 40 and comprises an inner surface 46 and outer surface 48 . most preferably , the top surface of the closure is a pierceable self sealing material whereby entry can be made into the tubular membrane through entry port 34 or into the vessel by sampling port 36 by means for example by a hypodermic needle so that fluids can be injected into the tubular membrane and / or added or removed from the vessel without breaking the environment of the vessel . after the needle is removed , the self sealing material immediately reseats . the material is most preferably an elastomeric material . tubular membrane 16 may be made from any suitable gas permeable material so long as it provides for the passage of fluids such as drugs and biological fluids into vessel 12 . preferably , the tubular membrane is made from a polymer or a dialysis material . the diameter of the tubular membrane is about 150 micron to about 300 micron and most preferably about 150 microns um . the length of the tubular membrane is dependent on the size of the vessel being used . the passage of solute through the tubular membrane will occur by one of two primary mechanisms . membranes , not having pores , such as these made from polyethylenteretholate ( pet ), as shown if fig4 will permit diffusion by the solubization of the solute in the membrane . the second mechanism for the passage of a solute through a membrane having pores 70 of about 0 . 02 , micron to about 2 . 0 micron and most preferably at about 0 . 5 microns as shown in fig5 is by a tortuous path as further shown in fig6 . in the tortuous path , the browian movement of the solute 72 causes it to enter the tortuous pore channel 74 and it thereby passes through the membrane and reaches an exit side 76 of the pore . priming volumes of about 0 . 25 ml to about 2 . 5 ml with macro fibers of about 2 . 5 ml to about 5 . 0 ml . the solute permeability of the tubular membrane may be small , medium or large . an example of the solute permeability are as follows : ( i ) a small solute permeability is about 50 to about 5000 molecular weight ( i . e ., urea , or insulin ); ( ii ) a medium size solute permeability is about 6000 to about 37 , 000 molecular weight ( i . e ., insulin , or heparin ); and ( iii ) a large molecule permeability is about 150 , 000 antibodies . an example of a commercially available tubular membrane is accurel pp capillary membranes ( trademark of akzo , germany ). the accurel pp capillary membranes that may be used in the present invention have the following characteristics : ______________________________________accurel designation type v8 / 2 s6 / 2polymer polypropylene polypropylenenominal pore size , um 0 . 2 0 . 2maximum pore size , um ≦ 0 . 65 ≦ 0 . 65bubble point versus ipa , bar ≧ 0 . 95 ≧ 0 . 95retention of pseudomania ≧ 8 ≧ 8diminuta , log reduction valuetrans membrane flow ( ipa ≧ 0 . 9 ≧ 2 . 525 ° c . ), ml / min cm . sup . 2 barextractable ( armostat ), ppm ≦ 500 ≦ 100wall thickness ( mean value ), 1500 450μmrange of mean value , μm 1350 - 1650 380 - 520inner diameter ( mean value ), 5500 1800μmrange of mean value , μm 5300 - 5700 1600 - 2000implosion pressure ( 25 ° c . ), ≧ 2 . 5 ≧ 8barburst pressure ( 25 ° c . ), bar ≧ 8 ≧ 8______________________________________ the present invention in use , as shown in fig7 a cell media 60 is injected into the vessel by the tubular membrane at the entry port by means of a syringe or the like . the closure and tubular membrane is rotated as the fluid is being delivered through the entry port , into the tubular membrane and thereafter it is distributed into the vessel . the closure is rotated to reduce media protein boundary at the outer surface of the tubular membrane and also to facilitate stirring of the cell media in the vessel . if desirable , further substances can be injected and / or withdrawn from the vessel through the sampling port , such as medium from the vessel for drug analysis . the injectable feature of the tubular membrane permits the investigator to alter the kinetics of the tubular membrane diffusivity by pre - injecting the tubular membrane with surfactants to accelerate the drug release . the tubular membrane may be used to distribute substances such as drugs , hormones , insecticides , phomones and repellents into the vessel . the tubular membrane provides a means for the controlled release of the active substances wherein the substrate consists of an asymmetric wall formed from polymers . an alternate embodiment of the present invention as shown in fig8 includes many components which are substantially identical to the components of fig1 - 3 . accordingly , similar components performing similar functions will be numbered identically to those components of fig1 - 3 , except that a suffix &# 34 ; a &# 34 ; will be used to identify those similar components in fig8 . closure 14a as shown in fig8 is an alternate embodiment of the closure that can be used with vessel 12 . the alternate embodiment of the invention as shown in fig8 is that a second tubular membrane 52 is attached to the top of the closure at a second entry port 54 and extending into the vessel and a third tubular membrane 56 is attached to the top of the closure at a third entry port 58 and extending into the vessel . although fig8 only shows three tubluar membranes , it is well within the purview of the invention to have more than three tubular membranes extending into the vessel and / or attached to the top of the closure . multiple drugs can be delivered simultaneously or sequenced for agonist or antagonistic effects . typical uses could be changes in parameters such as temperature , different cells organisms , different gaseous environments , different media and additives .